SEA Homeschoolers is partnering with the Teacher Institute for Evolutionary Science (TIES), a division of the Richard Dawkins Foundation, to offer a series of lectures for our homeschool community. Filled with great information on teaching evolution to middle schoolers, these lectures are suitable for all ages. Attend and ask questions from your own computer absolutely free!
Visit the TIES website for tons of links to free resources on teaching evolution.
This is the first time that TIES has collaborated to bring these resources to homeschoolers, and we are thrilled to be a part of it. Spread the word and be sure to register for these great lectures!
Register now for the following lectures:
Wednesday, September 12, 2018 8:00 pm – 9:30 pm EDT
“Meeting Naledi – The Discovery of Our Nearest Human Relative”
Join SEA Homeschoolers as TIES teacher John Mead shares with us a presentation about the greatest human fossil discovery since Lucy! This presentation for all ages will cover how these fossils were recovered and studied. For more details and to register for free, visit the registration page.
In September of 2013, dedicated amateur cavers in South Africa exploring beyond the edges of the well-known Rising Star Cave came across a collection of human looking bones. Over the following months, a remarkable team building effort led to the discovery of the richest early human fossil site on the African continent and the naming of a new species – Homo naledi. TIES teacher John Mead will share his experience getting to know and work with the team and detailing the once-in-a-lifetime experience of how these new fossils were recovered and studied. If you do not know about the greatest human fossil discovery since Lucy, then please join us for John’s presentation.
Wednesday, September 26, 2018 8:00 pm – 9:00 pm EDT “The Evolution of Human Skin Color”
Join SEA Homeschoolers as Dr. Leslie Jones deconstructs the misconception that “race” has any biological basis in this presentation, and take away lessons you can use with your learners. For more details and to register for free, visit the registration page.
Genomic technologies have recently led to a dramatic increase in our understanding of relationships among early members of our species. With access to genetic markers that distinguish different populations, we have been able to reconstruct a much more accurate picture of migration out of Africa and the various paths our ancestors took on the way to the colonization of most of the world. As a biologist who is committed to using science education to deconstruct the widely held notion that “race” has any biological basis, Dr. Jones has developed lessons on human evolution that explain visible diversity within our species. The centerpiece of this approach is why skin color, the ultimate marker for racist distinctions, varies within indigenous populations. These lessons are always coupled with explicit instruction on the history of how racial categories were fallaciously invented to justify European imperialism and the social construction of race.
These sessions can fill up, so be sure to reserve your spot right away.
Watch for details on future TIES lectures:
Date to be announced: Classifying Life (Phylogeny and Cladistics)
Date to be announced: The Theory of Evolution Explained
Check out our review of Pandia Press Astronomy 1 here.
How the Scientific Theory of Evolution Was Developed, and How and Why It Continues to Evolve
(As All Good Scientific Theories Should)
For all the controversy surrounding evolution, you would be justified in thinking the theory of evolution stands on shaky ground as far as the scientific method goes. In fact it was through standard, rigorous applications of the scientific method that scientists came to their current understanding of the evolutionary process.
Science investigations begin with one or more questions about phenomena observed in the natural or physical world. The theory of evolution attempts to answer three basic questions: Why are there so many different forms of life, when based on environmental conditions there could be fewer? Why have most species gone extinct with others taking their place in the environment? How did the many different types of organisms come to be?
Before looking at how the scientific method was applied to the Theory of Evolution, it is important to understand that the Theory of Evolution, was not developed from one hypothesis or one study. Biological evolution is genetic change in a population occurring over several generations. That evolution happens is a fact. It is a fact that populations of organisms evolve. (The science supporting this statement is very solid, and so substantial it would take several lengthy books to share all of it.) The theory of evolution attempts to explain how and why evolution has happened in the past and continues to happen today. The theory of evolution has many different parts, each one attempting to give more information about how and why organisms evolve. Applying the scientific method to specific limited aspects that look at how and why evolution occurs, has resulted in a well-substantiated, multi-varied, and complex scientific theory.
Every well-done experiment conducted in the field of biology uses and supports the Theory of Evolution. This is because at its most basic, the theory of evolution is the foundational tenet of biology. Countless well-done experiments have been conducted that have improved our understanding of evolution. Because of this I am going to limit down the examples I use for this article. I would like to show you how the scientific method has been applied to develop this theory and how the understanding of the Theory of Evolution has evolved through continued investigations using the scientific method. Every well-done experiment in science uses the scientific method. Science is not just a collection of facts. It should not be taught that way, and it cannot be adequately learned that way. Science is a method. To really understand science, it is essential to understand the method used by scientists to develop scientific theories and scientific models. Understanding this method is essential to understanding how scientists develop both of these and why these theories and models can and should evolve through continued experiment.
It Starts with a Question
Observations are not just made during an experiment. Before scientists develop a hypothesis they make observations about something in the natural or physical world. It is from these initial observations that scientists come up with what they are going to study in the first place. After initially wondering why something is happening, scientists continue observing the phenomenon until they think they have a possible answer. This is where the process of developing an hypothesis begins.
A Possible Answer to the Why and How: The Hypothesis
Jean Baptiste Lamarck hypothesized that traits organisms acquire in their lifetime can be inherited by their offspring. For example, the offspring of a long-distance runner could inherit his parent’s ability to run long distances. We now know that Lamarck’s proposed mechanism for evolution was incorrect. He was correct, however, in hypothesizing that organisms inherit traits from their parents, and that inheriting these traits can result in the traits becoming more common in populations of organisms. In other words, he was correct that populations of organisms evolve.
Charles Darwin agreed with Lamarck that organisms evolve. Darwin hypothesized a different mechanism for evolution, called natural selection. Natural selection is the process where organisms have a better or a worse chance of survival because of their traits. According to Darwin, over generations organisms with beneficial traits live longer and have more offspring. Therefore they are more likely to pass their traits on to their offspring than those organisms with harmful traits. This results in the natural selection of beneficial traits, which therefore become more common within a population than harmful traits. Darwin’s mechanism for evolution was only part of the story. Scientists now understand that there are other mechanisms for evolution in addition to natural selection.
Gregor Mendel hypothesized a mechanism for how traits were inherited. Mendel proposed that organisms have a pair of factors inherited in discrete, unchanging units, now called genes, that control the appearance of a given trait, and that organisms inherit these traits from their parents. Mendel was correct when he proposed that discrete units control traits and are inherited from an organism’s parents. We now know, however, that Mendel was only partially correct when he proposed that genes are unchanging units. Sometimes genes do mutate and change.
To Be Meaningful in Science the Hypothesis Must Be Testable: The Procedure
Once a hypothesis has been proposed, the scientist needs to put together a plan, a procedure, for how they are going to rigorously test their hypothesis. It is important that the procedure be very specific to the hypothesis. A good procedure is detailed and complete enough that another scientist can duplicate the experiment exactly. It is essential that the experiment be well-controlled and that the procedure focuses narrowly on the specific observations the hypothesis is based on.
The procedures scientists use today are much more sophisticated than those used by Lamarck, Darwin, and Mendel. There are two reasons for this. The first is that the work of these three men has been repeated enough that there is no need to continue to repeat the experiments. The second is that the tools used today are more advanced. Modern tools enable scientists to look at organism’s cells, cell structure, and genetic makeup.
Testing the Hypothesis: Conducting the Experiment and Making Observations
Once a procedure is decided upon it is time to conduct the experiment. If the observations confirm the hypothesis the researcher must do two things. First they must re-examine the procedure to make sure there isn’t another possible answer for what they are observing. After that the scientist needs to repeat their experiment many times. Mendel, for example, used thousands of pea plants for his experiment, which he repeated many times over several years.
If the observations are not what the scientist expects they need to look at their procedure to see if the problem is with it or if all or part of their hypothesis needs to be rejected. Lamarck’s hypothesized mechanism for evolution was discarded based on casual observations. Sometimes, though, the answer to what is being observed isn’t as easy to figure out. Darwin’s hypothesis that natural selection is the mechanism for evolution is a good example. Darwin was correct that populations can evolve through natural selection, but there are other mechanisms of evolution. It was observable that populations sometimes evolve in ways that are harmful.
“Mutation, migration, and genetic drift may cause populations to evolve in ways that are actually harmful overall or make them less suitable for their environments. For example, the Afrikaner population of South Africa has an unusually high frequency of the gene responsible for Huntington’s disease because the gene version drifted to high frequency as the population grew from a small starting population. Finally, the whole idea of ‘progress’ doesn’t make sense when it comes to evolution.” http://evolution.berkeley.edu/evolibrary/misconceptions_faq.php#b1
That means Darwin’s hypothesis would sometimes be invalid and sometimes be confirmed. When this happens, the researcher must determine if the hypothesis is too big and possibly needs to be narrowed down. For example, Darwin’s hypothesis could be corrected to say “natural selection is a mechanism for evolution”.
Analysis: The Data and Results
A meticulous analysis of the data and results is critical. This is what the conclusion is based on. Once a scientist concludes that his data and research gives him specific answers about a process, he shares his research including the data and results. Other scientists pore over the data analysis looking for holes and missteps. It has been through the meticulous analysis of the data and results from vast numbers of experiments conducted by many different researchers that scientists have come to understand that evolution occurs, and they have come to some conclusions about how and why it occurs.
A More Complete Understanding: The Conclusion
If you think of a theory as a puzzle, the conclusion from each experiment is a piece of the puzzle. When the conclusion is that the hypothesis is incorrect, then the puzzle piece doesn’t fit, and doesn’t give information about that theory. It does, however, give information about what isn’t happening, which is important information.
A conclusion that validates the hypothesis gives information about the theory, but it isn’t the entire completed puzzle. Instead it leads to a more complete understanding of the pieces that make up the theory. Once the conclusion has been accepted as a sound explanation through numerous experiments conducted by numerous scientists, more and new experiments (all using the scientific method) can be built from that piece. Just like a puzzle piece, the experiment gives information about how to build a complete picture from the pieces already in place.
Lamarck, Darwin, and Mendel all contributed to our understanding of the Theory of Evolution. Each of them observed something in nature, hypothesized a possible mechanism explaining what they observed, tested hypotheses, meticulously analyzed data, and came to conclusions based on experiments. Through years of applying the scientific method by these scientists and others, it was shown that part of each of their hypothesis was valid, and part was incorrect or incomplete. That is how science works, through stops and starts, failed experiments and successful ones. That is how researchers arrived at today’s Theory of Evolution. This is a theory that will continue to grow and evolve as more experiments, all using the scientific method, are conducted. These experiments will build on those areas where an understanding of the process is solid, and attempt to find answers for those areas where science, as of yet, does not have an answer.
This was originally published on the Pandia Press blog: http://www.pandiapress.com/blog-post-list/
Sean woke me up early. “Mom, I have broken out in a bad rash, or bites, or something all over!” Well, that will get a mother up and going! We could not figure it out. No one else had any bumps. Could it be that Sean was allergic to the detergent used when we washed clothes, or maybe it was the 30 to 40 nispero (fruits from the tree in the backyard) he ate over the course of 1&1/2 days? We still are not sure. In two itchy, scratchy days they were gone. It did get us going earlier than expected though.
The night before we finally planned the last bit of our trip. We would spend 1 night getting there, then stay in Sitges for three days. Sitges is a small beach community just south of Barcelona and north of Tarragona. The last night we would stay at an airport hotel in Barcelona. Today we would drive to Orce, Spain and sleep where the wind took us as long as it was in the direction of Sitges.
You might think the pronunciation of Orce is ors, but it is orth, with the th drawn out. Early in our trip. Jim noticed it sounded as if people were saying grathious instead of gracious. At first he thought it was a lisp. He quickly realized the entire population of Spain most likely did not have a lisp. When he asked about it, it was explained to him that the c is often (but not always) pronounced as th.
When I heard there were mammoth fossils being excavated in the Granada area, I Googled it right away. Not only have they found mammoth fossils, but they found the remains of humans dated to over a million years old. This sort of detour is why we prefer to travel like we do. It does mean that sometimes we cannot get the tickets to a palace we would otherwise visit, but it also means we have the flexibility to take an unplanned detour to see fossils.
Traveler’s Tip: If you visit the Orce area between July 6 to September 7, you can visit one of the digs with people working at them. If you read about it here and go, I want photos! I will be super jealous, but I still want to hear about it!
We like to travel off the beaten path. Orce, Spain qualifies for this. We were the only 4 people in the entire museum. They unlocked it for us. Gave us some cards explaining what we were looking at, and left us to look. I should start a hashtag #PlacesInSpainWithNobodyThere. Here is what is sad, people should be visiting these places. These places have all been seriously cool.
I am including photos from literature given to use while visiting the museum.
It is now thought that the first people living on the European continent lived in Southern Spain and were from Africa. Looking at the geography this makes sense. Some scientists think people were living in Europe as early as 1.8 million year BCE. It is thought there might have been a land bridge between north Africa and the Iberian Peninsula. The countries of Spain, Portugal, and Andorra make up the Iberian Peninsula.
When Orce man was discovered there was great excitement in the scientific community. It was then suggested that the fragment was that of an equine species. Tests done since support the scientific theory that the fragment is of human origin. The other evidence that has been excavated in Orce are several human teeth and stones that have been sharpened to make tools. Until I was back in the States I did not appreciate what I was looking at when I looked at the skull fragment. In Orce, I was more excited about the tooth on display. Little did I know that the skull fragment was one of the key pieces of “evidence” creationists use when attempting to discredit the occurrence of evolution. The skull fragment was found at one of the four excavation sites surrounding Orce.
What the creationists say about Orce man.
Orce man: Found in the southern Spanish town of Orce in 1982, and hailed as the oldest fossilized human remains ever found in Europe. One year later officials admitted the skull fragment was not human but probably came from a 4 month old donkey. Scientists had said the skull belonged to a 17-year-old man who lived 900,000 to 1.6 million years ago, and even had very detail drawings done to represent what he would have looked like. (source: “Skull fragment may not be human”, Knoxville News-Sentinel, 1983) http://www.nwcreation.net/evolutionfraud.html
The statement is misleading and they do not use a solid science reference. it also has not been updated to include the latest evidence using albumin analysis, http://link.springer.com/article/10.1007%2FBF02436194#page-1, which isn’t very new, but I thought you would find it interesting.
I had no idea when I chose science as a discipline of study, that I was heading down a path with controversy. I am a secular, academic, homeschooling scientist who writes about evolution, the Big Bang, human causes of climate change, and living on a multi-million year old planet in a multi-billion year old universe, though, so… As you can imagine, I was over the top excited when I realized I saw the oldest human fossils to be discovered on the European continent!!!
We drove for the night until we were ready to be done. This put us near Peniscola where we found a room for the night. I read about it on my phone and it sounded like a good place to stay. This is where the Spanish tourists hang out. (In droves! It felt like the beach area in California in the summer on steroids!) The people were friendly, the beach lovely, and we could not wait to get out of there the next morning. Imagine a Disney Hotel at max capacity and then add more people!
People kept asking if we were British. I asked, and was told that is because Peniscola is not a destination Americans go to. It was eye-opening though, and I am glad we stayed, because now we know the Spanish do vacation. When I said something about the hotel staff not being able to distinguish between a U.S. and British accent Sean made a great point. He asked why someone who barely speaks English would notice the difference. Several people told me I speak Mexican Spanish. Sean pointed out that I couldn’t tell the difference between that and Castillian Spanish.
After dinner we rode around Peniscola in a pedal cab. Sean and Jim did most of the peddling. Then Sean took over and did it all. Just one of the perks of bringing a fit 15-year-old boy with you! We were laughing so hard. Don’t you love the sound of kids laughing!
Here is a list of the articles I read about the fossils in Orce.