Climate Change & Size Evolution (Updated)

Have you ever wondered why the species from the dinosaur era were much larger compared to the species that exist today? Why do some species tend to be larger than others? The size of a specie is one of the most essential characteristics that resemble how a specie should live. Various perspectives regarding the size of species depending on the climate have been introduced by numerous scientists. It is a very controversial topic to review but, I intend to summarize my findings and would be delighted to know about how others believe climate change and global warming will have impact on the size evolution in the near future.

I will begin by reviewing the discovery of a 60-million year old fossil believed to be a snake that weighed approximately 1140kg and measured 13 meters in length. This magnificent fossil referred to as the “Titanoboa cerrejonensis” was uncovered by the University of Florida’s Florida Museum of Natural History and a crew directed by  the Smithsonian Tropical Research Institute. Soon after the discovery, the fossil was examined by Jason Head from the University of Toronto-Mississauga who made the estimates of the approximate temperature of Earth 60-million years ago (the period in which the Titanoboa cerrejonensis lived). Scientists believed that only a very hot climate would be enough to support cold blooded creatures such as this snake. Paleontologists stated that cold-blooded reptiles tend to be larger when they live in a hot climate as correlation studies indicate that as temperature rises, the upper body of poikilotherms which are cold-blooded creatures also increases in size proven by the size of their bone structure. So exactly how much hotter would the Earth have to be to support a snake as big as this? It is believed that tropical ecosystems that supported creatures such as this snake lived in rain forests such as Cerrejon at an average temperature of 32 degrees Celsius which is approximately 5 degrees Celsius higher than the average temperature of a modern rain forest. As a matter of fact, Jason Head from the University of Toronto and Jonathan Bloch from Florida Museum of Natural History indicated that  the Titanoboa cerrejonensis required a minimum average temperature of 30-34 degrees Celsius to survive.

The Titanoboa cerrejonensis fossil vertebra is placed alongside the vertebra of a modern day, 10-foot-long boa constrictor. The two vertebrae are both positioned near the snake’s bellies. -Jason Head et al.

Now some of you reading this may say this has not proven or has given any reason to why animals in the dinosaur era used to be a lot bigger than the modern days’ creatures. This is where the real scientific explanation begins. Scientist believe that the main reason for massive and enormous size of species were due to the flourishing atmosphere that contained an immense amount of oxygen and carbon dioxide. As a matter of fact, the level of oxygen was 50% higher while the carbon dioxide was at the limit of 500% compared to today. Oxygen and carbon dioxide are two of the most important components that help plants grow faster and larger. With such hot conditions, not only oxygen and carbon dioxide was abundant but, hard rain and sunlight would also be very constant. In an environment and atmosphere such as this, not only the ordinary plants we see today may have been much larger but, various unknown plant life may have been abundant. I myself, even come to believe that some form of plants may have given unreal yet rich nutrients to these species, helping the species in the dinosaur era to develop much quicker and grow bigger. We cannot be sure what these unreal plants may have been, it may have not even existed as it is a personal statement unapproved by scientific evidence. Yet, I would still like to include such statement because we do know for a fact that the ecosystem at the dinosaur era was a lot different compared to the one we live in today. In addition, I would like to believe this and perhaps support this on my next blog because even today, we know for a fact that certain plants grow only at certain environments and conditions such as the “Blue Gum” that only grow in rain forests. Carrying on, as plants grew very large and was abundant during the dinosaur era, herbivores (plant eaters) ate as much of the resources that they were given and grew bigger. In addition, as herbivores grew bigger, it benefited the carnivores as there was plenty to eat for the carnivores. It was a matter of rich supply within the food chain supporting the growth and development of these species.

Scientific studies indicate that climate and the environment surrounding the species are leading factors that determine the size of species. As I said before, this is a very controversial topic that includes various perspectives on climate change and size evolution. As a matter of fact, some theories indicate that global warming will and is causing species to become smaller as time passes by while others state otherwise in the case of the Titanoboa cerrejonensis which is opposite as it states that as temperature is on the rise, cold-blooded creatures increase in size. For further information and inquiries on the general theory that supports why certain species get larger while some get smaller as temperature increases, you may want to read the link below which explains a case and validity of the Bergmann rule that states

Animals tend to become bigger as latitude increases or the climate gets colder, and animals found in warmer climates are generally smaller.

The purpose of this blog is to inform my audience that size evolution in species is also a topic that deserves more attention as global warming is on the rise. The impact of climate change will ultimately affect our food chain as size of species evolve and become larger or smaller. With uncertainty, we cannot be sure if a cat will become the prey of a mouse that becomes larger while the cat becomes smaller due to the climate change (Will probably never happen but just hypothetically). The previous statement just indicates that certain species that may have been weak in our modern world may prevail to become very dominant and powerful species in the future, threatening certain species. At worst, some species may become extinct and affect the entire food chain. We cannot predict how all of the different species will adapt to the new climate but perhaps this topic may show numerous individuals an additional reason to why we must do everything we can to stop global warming. This topic raises several questions into the future such as:

“If certain species become larger while some become smaller how will it affect the food chain? How do we preserve the lives of certain species that may become close to extinction?” ….or is climate change and size evolution just a total nonsense to you??? I am looking forward to many of your opinions.

This entry was posted in Uncategorized. Bookmark the permalink.

9 Responses to Climate Change & Size Evolution (Updated)

  1. avatar Pratheep says:

    Hey bro
    Good on you for raising a controversial topic!

    I see u mentioned that higher temperatures could possibly be one cause for the enormous body size of dinosaurs. U also mentioned that organic compounds such as CO2 encouraged growth.
    The thing I dont understand is that a large surface area:volume ratio of the dinosaurs would cause the cooling of the animals to be a long process. The smaller the surface area:volume ratio, the better the organism will be at cooling down or heating up. If the planet was so hot the dinosaurs would have had a horrible time cooling down which is essential for biochemical function of the body I wonder if the fact that dinosaurs were reptiles enabled them to override this condition?

    I hope my facts are straight. Dont hesitiate to call me out if im wrong though.
    thnx for the great post. Pce!

    • avatar Tony says:

      Hey Pratheep,
      I understand what you are saying and totally see the logic on the points you’ve made. My research was more concentrated on the environmental influence on size evolution of species so I did not include drastic information on the anatomical feature of the species. To be honest, now I think that you’ve touched on some relevant points that I should look into. I will attempt to follow up on changes the biochemical function of species may go through for my final draft!
      Best, Tony.

  2. avatar Nathan Urban says:

    As your post suggests, there have been some critiques of the claim that the Titanoboa fossils imply a very warm tropical paleoclimate. (Or at least, as warm as was originally claimed.) See the followup comment papers here, here, and here.

  3. avatar Tony says:

    Btw does anyone know why I am not able to upload some pictures onto my blog? It’s wierd because I uploaded ONE picture….I have other pictures I that I would like to upload but everytime i try it won’t let me. It suggested me to dismiss it because it couldn’t “upload” it…but i forced it anyways and seems like those pictures came out blank with a red…”x”!!!

    • avatar Pratheep says:

      yeah i had some trouble uploading some pictures from my hard drive as well. I havent found a fix yet. But pics from the net seemed to work fine everytime though

  4. avatar Abayomi says:

    This is very interesting. I am wondering how many people have heard of this aspect of climate change. How many people are thinking of the size of animals in the future, big reptiles and small mammals maybe. I think a biology class will be very interested in this aspect of climate change and in investigating it. This information can help to get biology students interested in climate change in general and can perhaps form part of one of their courses. One important thing about educating people about climate change and getting them interested, is finding an area that they can understand and have a passion for. I am interested in how a biology course or part of a course could be constructed to teach biology students about this climate change from this angle, “The effect on animal life in the future”.

  5. avatar Tim van Beek says:

    Hi Tony,

    when talking to an audience of scientists, it is important to cite references when making claims like “scientists believe”, or if you don’t do that, explain why you don’t (“I consider this to be so well established that I won’t discuss it here”.)
    Also, peer reviewed papers are the most trustworthy source, if you instead link to a blog of somebody else, it would be helpful if you add a short explanation of this source and why you believe that it is both interesting and trustworthy.

  6. avatar jp says:

    Hi Tony,

    Looks like you’ve got some good feedback already. Here’s mine:

    Choice of topic:
    – It’s not entirely clear to me how this topic is related to the challenge of climate change. I think you’ve done a solid job explaining the how climate and species size are related, but it’s only at the very end of your post that you start to connect this phenomenon up with the challenges (e.g. extinction) and tell us why it may be important. I suggest exploring more on this and including it in your post.

    Use of resources:
    I think Tim Van Beek’s comment is spot on. Your post could use more specific references to the scientific research. Blogs and news articles are okay, but digging a bit deeper to find the scientific sources gives your writing more credibility and saves your readers from having to do that work. I also think you need to be careful inserting your own opinions into a discussion of the facts (“I myself, even come to believe that some form of plants may have given unreal yet rich nutrients to these species”) unless you’re going to take the time to justify (with sources) why you believe that.

    You seem genuinely interested and write with an engaging style. At times you seem a little too casual (e.g. “This is where the real scientific explanation begins”.) Another thing I could suggest is a stronger conclusion that summarizes your post and answers the questions you asked in the opening paragraph.

    Watch out for a few minor spelling and grammatical errors (especially in your opening paragraph). You also provide a quote that “Animals tend to become bigger … as the climate becomes colder” which contradicts what you stated earlier in your paper!

    I think you’ve got a good start here.

    Good use of blogging features:
    Yup. The image is relevant, and nice job with the block quotations. You’ll definitely want to put your links to source material inline in the text, like so.

Comments are closed.