Jean-Baptiste Lamarck was one of the few that had
the most influence over Darwin’s development of his theory of natural
selection. Some scientists have argued to this day that Jean might have made a
theory not necessarily relative to the idea behind natural selection. However, when fully researching and gaining a
better understanding of his idea often shows how it could relate to genetics
and evolutional theory. Jean-Baptiste-Pierre-Antoine de Monet, chavalier de
Lamarck was his full name and he was a pioneer French Biologist of his time
period. He was born on the first of August 1744 and passed away on the 18th
of December 1829 in Paris, France. He proposed
the idea known as Lamarckism in which acquired characters are inheritable.
Lamarckism was a continuation of Jean’s mentor’s work. Jean was credited for
further developing the work of Count George-Louis Leclerc de Buffon. He was the first to ever propose a type of method
explaining how gradual changes of species came into place. Also extended the definition
of change over time, where life started out simple and became complex over as
life progressed.
There’s two parts to Lamarckism in which Jean
published Philosophie Zoologique in 1809 describing in depth the two parts to
the mechanism on how change was steadily introduced into species and later passed on to
the following generations. The very first part of Lamarckism is Use and Disuse
or also known as the altering influence of particular circumstances (how the
environment can affect gradation of a form). The example of the elongated neck
of a giraffe is great in explaining the concept. Based on the theory, a giraffe
is said to be able to develop an elongated neck after putting so much strain on
it when reaching leaves on high branches. There is quite a downfall when it
comes to this part because Jean never really fully explained how it was
possible for such process to occur. This example has been used in order to
explain how use can change a trait and how disuse would cause a trait to be
reduced and thus become unnecessary.
The second part to it would be the in depth of the
use and disuse method. That is the inheritance of acquired traits. Jean
believed that the traits that were changed or would change through use could be
passed down to its offspring. But this was only plausible if both parents
underwent an acquiring of traits during their lifetime. However, if one
individual who underwent acquiring of new traits mated with someone who simply
disuse and reduced a trait then all the peculiarities that were acquired would
then disappear and the offspring would not inherit such trait. This brought him
to believe if two individuals of a species were both exposed to the same
environment, they would equally respond and gain the same new habits. This is
where the belief of exposure to new circumstances happened to all living
organisms all over the world simply because it became subjective on every place
on the earth’s surface. That is also due to the fact of the altering of
climates, beds of rivers and oceans becoming displaced, some lands were elevated
while others eroded and many various factors in which contributed to modifications
of species. These modifications were indeed slow and incremental. They only
happened if the changes of a circumstance caused the animal to adapt new
habits. An extension explanation behind the idea of inheritance where
evolutionary change occurs steadily but it is constant. This proposal came from
his examination of seashells in which he noticed that as they aged the simpler
they looked. That’s when he concluded that all species started out simple and
as they gradually became older, they were constantly become more complex or in
other words becoming their true perfect form.
If Jean-Baptiste had not proposed such idea of
inheritance of acquired traits though he never really called it that, Charles
Darwin would have not been able to develop his theory of natural selection.
Charles Darwin took upon Jean-Baptiste’s idea and began to test it to see whether
he could find how it was plausible that inheritance of acquired traits was one
of the many plausible explanations of the theory of evolution. Jean might have
proposed such a great explanation with lack of evidence backing such idea at a
time where people didn’t put much attention to it but it Charles Darwin that
fulfilled the theory. He provided an in depth explanation as to how characters
acquired traits through use and disuse and how it was transmitted from
generation to generation. All in all he gave more evidence of the effect of use
and disuse. As he provided more examples to the idea of inheritance of acquired
traits he never mentioned or credited Jean-Baptiste towards his idea.
Charles Darwin had credible evidence to further
explain why he thought we all evolved over time. He had all the answers to how
the environment affected and enhanced the way of living for every species. As well
as the notion behind species first starting off as being simple and over time
becoming more complex. But the mind-set of the main people from the church
discouraged him from further publishing his work. The reason why the church was
angered at such theory was because it went against the belief that god was the
creator of all living species and the formation of the universe as it stated in
the bible. Nonetheless, we all were granted with being able to learn about
natural selection all thanks to another of Charles Darwin’s influences. That is
Alfred Wallace. Thanks to him for motivating Charles in publish his theory
despite of what the outcome might have been, we now have an in depth
explanation of theory of evolution.
For in depth explanation on Lamarckism, the following links would be quite helpful.
NCBI https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3730912/
Encyclopedia Britannica https://www.britannica.com/biography/Jean-Baptiste-Lamarck
This post was very informative! I took the same stance that Lamarck was the heaviest influence on Darwin's work, and I think your post is very strong in covering all aspects of their influence. The one thing I will say is, the post would be much more concise and less loaded if you cut out the unnecessary information, like where Lamarck was born and things of this nature. It doesn't add anything to the point, which is how he made his impact on Darwin. Despite that, it's still a strong post and it's very in-depth.
ReplyDeleteHi Stephanie!,
ReplyDeleteI really loved your post! I also had the same position that Lamarck had the greatest influence on Darwin's theory of natural selection and essentially his interest as well. I am in total agreement with you that if Lamarck had not came up with the idea that how organisms acquired traits through use and disuse and the inner need, Darwin's theory and interest would not have sparked. Although you have great information with a lot of very concrete details and analysis on Lamarck's contributions, I feel that you should shorten it up and cut the point a bit. Also, I think if you shorten it a bit and use more concise sentences, you could get rid of the fluff of information about when he passed away and his life story because all you need is a simple introduction to then elaborate more on Lamarck's point and contributions to Darwin's theory. Honestly, I think you did an amazing meticulous job, and I really liked the visual that depicted Lamarck's view on evolution and natural selection.
Good sources and good inclusion of images.
ReplyDeleteIn general, good explanation of Lamarck's work, with just a few misconceptions to clear up.
The "Use/Disuse" theory is another name for "Inheritance of Acquired Characteristics". "Use/Disuse" provides a more descriptive name for how the process occurs, with organisms responding to the environment by changing or even losing traits according to what they need and don't need in that environment. Those "acquired traits" are then passed onto offspring, perpetuating these new traits in the next generation.
But beyond that, let's look a little more closely at the differences in theories of Lamarck and Darwin. Lamarck's theory of the 'Inheritance of Acquired Characteristics' suggested that organisms can change during their lifetime in response to the environment, changing or even losing traits as needed. Those changes are then passed onto their offspring. The problem is that this isn't how our system of inheritance works, though neither Darwin nor Lamarck knew about "genes" or "genetics" at that time. A person's genetics cannot change during their lifetime as proposed by Lamarck. Darwin, in contrast, argued that the environment essentially chooses ("selects") the best of all available traits that are most advantageous in that particular environment through the process of those individuals possessing those advantageous traits having more offspring than those without, thus passing on those traits in greater number. That is how the population changes, but differential reproductive success, not by individuals themselves changing.
In the prior two sections, you identify two points, and I suspect you were addessing the prompt regarding "bullet points"? But that prompt is asking you to review the bullet point list in the assignment guidelines and identify the bullet points that lay the ground work for Darwin's theory that can be applied directly to Lamarck. There are four that I would argue apply to Lamarck.. for example, I would propose that Lamarck contributed directly to the point on the importance of inheritance in evolution. Take a moment to review that question again and the guidelines.
I agree that Darwin likely used some of Lamarck's work as a springboard to his own, but careful about over-crediting Lamarck for Darwin's theory. While Lamarck should be credited with the first attempt at proposing a working mechanism for evolution, that doesn't mean that he was the only scientist thinking and talking about evolution during Darwin's time. It was a relatively popular topic. Lamarck (who was not a contemporary of Darwin's) would have served as foundational information for Darwin, but only a part of that foundation, not necessarily a large enough influence to be required for Darwin to develop his theory.
Good final discussion. Just keep in mind that the Church didn't know about Darwin's theory until *after* he published it. But Darwin was well aware of the Church's stance on issues that contradicted its own teachings and this would have been sufficient to cause him to think twice (for 23 years) before publishing.