Nature World Today

Nature's Best Site

Human Progress Has Led to the Collapse of the Largest Land Mammals

by 53 Comments

At the end of the Cretaceous period 66 million years ago, mammals took over as the largest creatures on land. However, around 125,000 years ago during the late Pleistocene, these megafauna started disappearing, writes Ed Yong for The Atlantic. Today they are all gone, and according to a new study by Felisa Smith from the University of New Mexico, the blame lies with humans and our hominin relatives.

Smith and her colleagues examined how mammals have changed in size over time showing that when humans are around, the mammals that disappear are usually 100 to 1000 times bigger than those that survive. “Size-selective extinction is a hallmark of human activity,” Smith says. She believes that size-specific collapses started well before the ascent of Homo sapiens, probably dating back to the origins of Homo erectus, around 1.8 million years ago.

When hominins like Neanderthals, Denisovans, and modern humans spread through Europe and Asia, the average mass of mammals there halved, writes Yong. Later, when Homo sapiens entered Australia, the mammals there became ten times smaller on average. “When it got warmer or colder, it didn’t select for bigger or smaller mammals,” says Smith. “It’s only when humans got involved that being large enhanced your extinction risk.”

Editorial content

Modern humans have now become adept at killing medium-sized and smaller mammals. As Smith puts it, if all the species that are now threatened eventually go extinct, the largest mammal left on land will be the domestic cow.

Reader Interactions

Comments

  1. 526077 676172Having read this I thought it was quite informative. I appreciate you taking the time and effort to put this write-up together. I once once again discover myself spending approach to a lot time both reading and commenting. But so what, it was still worth it! 696857

  3. 13182 983713 I discovered your blog web site on google and check some of your early posts. Continue to maintain up the really excellent operate. I just additional up your RSS feed to my MSN News Reader. Seeking forward to reading much more from you later on! 848338

  4. 804055 351400I dont feel Ive scan anything like this before. So great to discover somebody with some original thoughts on this subject. thank for starting this up. This site is something that is necessary on the internet, someone with just a little originality. Excellent job for bringing something new to the internet! 579417

  5. 965644 395915This internet website is generally a walk-through its the data you wished concerning this and didnt know who ought to. Glimpse here, and youll surely discover it. 128204

  8. 106872 702761Wow, remarkable weblog structure! How long have you been running a blog for? you created running a blog look simple. The whole look of your website is magnificent, neatly as the content material! 157230

  13. 344843 70996Well written articles like yours renews my faith in todays writers. Youve written data I can lastly agree on and use. Thank you for sharing. 922310

  14. 823059 834536Utilizing writers exercises such as chunking. They use a lot of websites that contain several creative writing exercises. Writers read an exercise, and do it. 643141

  15. 722887 561357Youre so cool! I dont suppose Ive read anything like this before. So nice to locate somebody with some original thoughts on this subject. realy thank you for starting this up. this web site is something that is needed on the internet, someone with a bit originality. helpful job for bringing something new towards the internet! 239229

  16. 595638 116812A thoughtful opinion and ideas Ill use on my web page. Youve clearly spent some time on this. Properly carried out! 541590

  19. 797804 350441Howdy! Would you mind if I share your blog with my twitter group? Theres lots of people that I think would actually enjoy your content material. Please let me know. Thanks 310267

  21. 220176 748688Hello! I could have sworn Ive been to this website before but following browsing by way of some of the post I realized it is new to me. Nonetheless, Im surely pleased I discovered it and Ill be book-marking and checking back regularly! 179163

  22. 863065 983244Aw, this was a quite good post. In thought I want to put in writing like this moreover ?taking time and actual effort to make a extremely very good article?however what can I say?I procrastinate alot and certainly not appear to get 1 thing done. 92215

  24. 750523 803240Hey there. I want to to inquire somethingis this a wordpress weblog as we are thinking about shifting over to WP. Also did you make this theme on your personal? Thanks. 742345

  27. 56369 51109There is an ending. Just remember that I meant for this to be an art game. I do feel like I spent an inordinate amount of time on the more traditional gameplay elements, which may possibly make the meaning of the game a bit unclear. In case you mess about with it though, you will find it. 564320

  29. 844002 484293Come across back yard garden unusual periods of ones Are normally Weight reduction and every one one may be important. One way state could possibly be substantial squandering by way of the diet. shed weight 753148

  30. 197667 92359Hello! I just now would pick to supply a enormous thumbs up with the great information you can have here within this post. I will be coming back to your weblog internet site for additional soon. 169063

  34. 278600 369687amazing post, very informative. I wonder why the other experts of this sector do not notice this. You need to continue your writing. Im positive, youve a great readers base already! 261832

  36. 853689 469964Admiring the time and energy you put into your blog and in depth info you offer. It is excellent to come across a weblog every once in a even though that isnt exactly the same old rehashed material. Amazing read! Ive bookmarked your website and Im adding your RSS feeds to my Google account. 774851

  38. 732482 329796bless you with regard to the specific weblog post ive genuinely been seeking with regard to this kind of advice on the net for sum time these days hence with thanks 356663

  41. 13816 901260When I originally commented I clicked the -Notify me when new surveys are added- checkbox and from now on whenever a comment is added I purchase four emails sticking with exactly the same comment. Perhaps there is by any means you might get rid of me from that service? Thanks! 784342

  43. 692894 165815Oh my goodness! a wonderful post dude. Thanks Nevertheless My business is experiencing concern with ur rss . Dont know why Not able to sign up for it. Possibly there is any person obtaining identical rss difficulty? Anyone who knows kindly respond. Thnkx 206983

  52. When I read an article on this topic, baccaratsite the first thought was profound and difficult, and I wondered if others could understand.. My site has a discussion board for articles and photos similar to this topic. Could you please visit me when you have time to discuss this topic?

Leave a Reply

Your email address will not be published.