Nature World Today

Nature's Best Site

Humans Likely Caused Mammals to Shrink, Study Reports

by 41 Comments

Ancient humans may be the reason mammals have significantly shrunk in size over the past 125,000 years, according to a new study in the journal Science. This research comes from scientists at various U.S. universities, who discovered the trend by analyzing fossils going back 65 million years. They found that size did not play a role in mammalian survival until humans came about, Tech Times reports.

While large and small mammals both thrived for a while, humans rapidly shifted that balance. Data showed that when humans settled in a region the chances of survival for large mammals significantly dropped. In fact, as humans moved out of Africa large animals often went extinct wherever they went. That same trend showed up in the Americas as well. 

“The only time we see a spike in extinction rates and this huge size bias, where large-bodied things are disproportionately at risk, was where hominids are involved,” said lead author Felisa Smith, a researcher at the University of New Mexico, according to Seeker. “From that, we conclude that it’s probably related to human exploitation of large-bodied animals.”

Editorial content

The team found that as humans spread general animal size declined. The average body mass of mammals in Eurasia dropped by half over the course of 100,000 years, and species in Australia lost 90 percent of their mass over the last 125,000 years.

That is likely the result of hunting, but it is also possible that many larger mammals were killed because early humans feared them and saw them as threats. In addition, the burning of forests and grassland may have led to that shift.

“From a life-history standpoint, it makes some sense,” said study co-author Kate Lyons, a researcher at the University of Nebraska-Lincoln, according to USA Today. “If you kill a rabbit, you’re going to feed your family for a night. If you can kill a large mammal, you’re going to feed your village.”

Such populations drops did only affect the species being killed, they also had a large impact on the environment. Researchers found that killing off large mammals caused the land to erode faster as well. In that way, further of this topic could help scientists better understand the different ways our ancestors shaped the world of today.

Reader Interactions

Comments

  2. 783425 751713Previously you need to have highly effective internet business strategies get you started of obtaining into topics suitable for their web-based organization. educational 498166

  7. 834924 782008An intriguing discussion is worth comment. I believe that you ought to write regarding this topic, it might not be a taboo subject but normally persons are too few to chat on such topics. To one more location. Cheers 905411

  8. 626628 826290 There are some intriguing points in time in this write-up but I dont know if I see all of them center to heart. There is some validity but I will take hold opinion until I appear into it further. Excellent write-up , thanks and we want much more! Added to FeedBurner as nicely 94856

  10. 660500 720865Immer etliche Firmen bentzen heutzutage Interimmanagement als innovatives und ergnzendes Gertschaft i. Spanne der Unternehmensfhrung. Denn hiermit wird Kenntnisstand leistungsfhig, bedarfsgerecht und schnell ins Unternehmen geholt. 220878

  11. 705653 928718Simply wanna input on few general points, The web site layout is perfect, the articles is truly very good : D. 442264

  14. 186348 668398Good day! Do you know if they make any plugins to protect against hackers? Im kinda paranoid about losing everything Ive worked hard on. Any guidelines? 117935

  16. 676055 540573i was just surfing along and came upon your weblog. just wanted to say excellent job and this post truly helped me. 448271

  18. 393085 778107hi!,I like your writing so significantly! share we communicate far more about your post on AOL? I demand an expert on this location to solve my difficulty. Possibly thats you! Looking forward to see you. 616285

  23. 961625 181960This sort of wanting to come to a difference in her or his lifestyle, initial typically Los angeles Excess weight weightloss scheme is really a large running in as it reached that strive. weight loss 981588

  25. 845815 618179I believe one of your advertisings triggered my internet browser to resize, you might well want to put that on your blacklist. 52979

  26. 614436 13690Aw, it was an very very good post. In thought I would like to set up writing similar to this moreover – taking time and actual effort to create a extremely great article but exactly what do I say I procrastinate alot and also no indicates manage to go done. 372763

  27. 412413 89989Official NFL jerseys, NHL jerseys, Pro and replica jerseys customized with Any Name / Number in Pro-Stitched Tackle Twill. All NHL teams, full range of styles and apparel. Signed NFL NHL player jerseys and custom team hockey and football uniforms 830402

  28. 183997 843418Echt tolle Seite. Rubbish bin eigentlich nur per Zufall hier gelandet, aber ich bin jetzt schon complete von der tremendous Seite beeindruckt. Gratuliere dazu!! Viel Erfolg noch durch der sehr guten Home-page mein Freund. 151064

  29. 250654 992787Your home is valueble for me. Thanks!? This internet page is really a walk-via for all with the info you necessary about this and didn know who to ask. Glimpse proper here, and you l definitely uncover it. 357710

  30. 12267 907292Cheapest speeches and toasts, as properly as toasts. probably are designed building your own at the party and will be most likely to turn into witty, humorous so new even. finest man toast 364197

Leave a Reply

Your email address will not be published.