ريتشارد دوكنز's Blog, page 745

Ancient Human Migration Route Marked by Snail Shell “Bread Crumbs”

Want to know the route humans took when they first migrated from Africa into Europe? Seems that they might have marked the path. Not like Hansel and Gretel, who consciously left bread crumbs. Ancient humans ate as they trekked. And they appear to have chucked aside the packaging for some of their slimy sustenance: snails.  

Conventional wisdom has been that humans initially traveled from Africa to the Near East, then up around the Mediterranean through Lebanon before heading into Europe some 40[,000] to 50,000 years ago. But recently, some scientists have theorized that humans made it to Europe first and then headed east.  

Now there’s more support for the old view that humans traveled through the Levant on the way to Europe–in the form of the shells of edible marine snails. The study is in the Proceedings of the National Academy of Sciences. [Marjolein D. Bosch et al, New chronology for Ksâr ‘Akil (Lebanon) supports Levantine route of modern human dispersal into Europe]

Researchers evaluated shells from an archaeological site dated to the Upper Paleolithic in Lebanon. The shells were mostly intact, except the tapered pointy tip had been removed—most likely for easier access to the meat inside.

The scientists calculated the age of the shells via a variety of methods. And they found that the snails dated back almost 46,000 years. The earliest evidence of modern human remains in Europe seem to be no more than 45,000 years old. The snail evidence thus adds weight to the hypothesis that ancient people passed through the Levant on their way to Europe. And not at a snail’s pace, either.

—Cynthia Graber

[The above text is a transcript of this podcast.]

The First Wild ‘Virgin Births’

Hank shares news about two unusual animals in crisis: the saiga, which have lost about half of their total population in the past month, and the smalltooth sawfish which has been found to reproduce in the wild, without sex.

Hosted by: Hank Green

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Sources:

saiga

http://www.newscientist.com/article/dn27598-mystery-disease-claims-half-world-population-of-saiga-antelopes.html?utm_source=NSNS&utm_medium=SOC&utm_campaign=hoot&cmpid=SOC%257CNSNS%257C2015-GLOBAL-hoot#.VWdm1FxVikp

http://dotearth.blogs.nytimes.com/2015/05/29/previous-mass-die-offs-of-the-endangered-saiga-antelope-hint-at-a-warm-wet-weedy-culprit-in-kazakhstan/

http://www.cms.int/saiga/en/news/more-10000-saigas-found-dead-central-kazakhstan

http://www.nytimes.com/2015/06/02/science/saiga-antelope-mystery-disease-die-off.html

http://www.cms.int/saiga/en/news/more-10000-saigas-found-dead-central-kazakhstan

http://www.merckvetmanual.com/mvm/generalized_conditions/hemorrhagic_septicemia/overview_of_hemorrhagic_septicemia.html

http://www.cms.int/en/news/update-more-27000-saigas-confirmed-dead-cms-sends-out-emergency-expert-mission

http://www.edgeofexistence.org/mammals/species_info.php?id=62

http://www.nature.com/news/mysterious-die-off-sparks-race-to-save-saiga-antelope-1.17675

sawfish

http://dx.doi.org/10.1016/j.cub.2015.04.018

http://www.ansci.wisc.edu/jjp1/ansci_repro/misc/project_websites_08/tues/Komodo%20Dragons/what.htm

http://sb.cc.stonybrook.edu/news/general/2015_06_01_parthenogenesis.php?=marquee3

http://www.eurekalert.org/pub_releases/2015-06/cp-ses052715.php

Watch Me Live At 9:30pm ET Tonight (6/5/15) on YouTube!

Tonight I am going to be interviewed by Andy Cowen of the ORLY Radio Show. The YouTube video box below that is now counting down to showtime will stream the discussion live once it starts at 9:30pm Eastern Time. Tune in live! (Or catch the video using this same link after the show!)

Rare “Sea Serpent” Washes Up Dead On California Beach

Plants and Animals





Photo credit:

Tyler Dvorak/Catalina Island Conservancy

A rare deep-sea creature was found dead on a beach earlier this week. The four-meter-long (13.5 foot-long) carcass is the second oarfish to end up on Catalina Island in under two years. The latest find gives researchers another exciting opportunity to gain a better understanding of the longest bony fish in the sea.  

Triceratops Teeth Become Plant-Slicing Knives as They Strategically Wear Down With Use

Plants and Animals





Photo credit:

(A) T. horridus. (B) Transverse view of lower jaw tooth. (C) Naturally worn slicing teeth in the lower jaw showing wear-induced bowing-out of the central regions of the occlusal faces (arrow) to form fuller-like implements. Erickson et al. Sci. Adv. 2015

The beloved three-horned dinosaur had teeth that were surprisingly complex—more so than many modern reptiles, even rivaling the complexity of mammal teeth. By having chompers that strategically wear themselves down with use, a Triceratops ends up with knife-like teeth that can finely slice through dense plant material. This allowed the master masticators to enjoy a richer, more varied diet. The findings were published in Science Advances this week.

Fossil Friday

Fossil Friday

This week on Fossil Friday, we have a beautiful little specimen collected in Stewartville, Minnesota. Dating from the Middle Ordovician, this specimen is 460 million years old—give or take twenty million. What is it? Guess right and win bragging rights for the week!

Chimps Are Capable Of Cooking Food

Plants and Animals





Photo credit:

135pixel/shutterstock

It might seem obvious why chimps don’t have tea parties; they’d make a massive mess for a start, but the ability to cook food requires surprisingly advanced mental skills. You need to be able to understand that taking the food and processing it will produce something different and, more importantly, wait while this happens.

Seals With Sensors on Their Heads Record Ocean Data in Harsh, Icy Waters

Plants and Animals





Photo credit:

University of St Andrews

For the last decade, seals with frickin’ sensors attached to their heads have been helping out researchers by collecting data from the far-flung, icy waters in which they live. This information is now part of a freely available data portal called MEOP (Marine Mammals Exploring the Oceans Pole to Pole). The online portal – one of the world's largest oceanographic databases for polar oceans – launched earlier this week, and it offers unprecedented details about the harshest parts of the planet.

Cretaceous Bird with Long, Ribbon-Like Tail Feathers Flew Over Gondwana

Plants and Animals





Photo credit:

Reconstruction of the Cretaceous fossil bird from the Araripe Basin, Brazil. Deverson Pepi

A 115-million-year-old fossilized bird with a pair of long, ribbon-like tail feathers is the oldest bird ever found in Brazil. It was about the size of a hummingbird, and it likely boasted bright colors, according to findings published in Nature Communications this week. 

Scientists Have Developed A Flying Tricycle

Technology





Photo credit:

Flike.

Scientists are making hoverboards, jetpacks and flying cars. What other futuristic, Hollywood-style modes of transport can they cook up? Teleportation devices? We wish. But they have engineered something rather wacky: a Star Wars-style flying bike, complete with your very own lightsaber.