Today's Image of the Day from <a href="https://earthobservatory.nasa.gov/">NASA Earth Observatory</a> features the island of Hainan, China’s southernmost province, in the South China Sea.



According to NASA, the photograph focuses on the landscape around Gangmen Harbor and captures many typical characteristics of Hainan: forested mountain terrain juxtaposed with dense populations.&nbsp;



With tropical beaches along its shoreline, the island spans approximately 1,300 square miles. Floating fishing villages can be found in the shallow waters of the inner bays.



China is a leading country when it comes to wild catch, and also produces about 60 percent of the world’s farmed fish such as carp and tilapia. Aquaculture sites are often paired with fishing ports for sufficient transport.



The photograph was captured by an astronaut onboard the International Space Station (ISS),&nbsp;



Image Credit: NASA Earth Observatory



---



By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

The island of Hainan in the South China Sea

Today's Image of the Day from NASA Earth Observatory features...

Because David was frightened of the bear's erratic behavior, he humanely put down the creature. He brought the bear, who still mystified him, to a local government officer who was just as puzzled. Photo Credit: brytta / Getty Images

Erratic Behavior

Because David was frightened of the bear's erratic behavior, he...

But the officer had a hunch as to what this bear-thing was. He figured it was some sort of hybrid, but to find out for sure, the officer sent the bear's DNA to a lab to be tested. They anxiously waited on the DNA results, but this was no episode of Maury. Photo Credit: ernestoeslava/Pixabay

DNA Testing

But the officer had a hunch as to what this...

The tests showed that years prior to David's discovery, 20 of these animals were born in captivity. But because these particular hybrid animals and their parents had been kept apart from the wild, where did David's blonde bear originate from? Photo Credit: Handout / Handout / Getty Images

Born In Captivity

The tests showed that years prior to David's discovery, 20...

Well, in 2006, a hunter found the first documented hybrid bear on Banks Island, Northern Territories, Canada, which is a bit northwest of where David found his hybrid in 2010. While those bears were never found to be particularly exciting or noteworthy to scientists, things changed in 2016. ArtTower/Pixabay

Emerging Hybrids

Well, in 2006, a hunter found the first documented hybrid...

Although chimpanzees (Pan troglodytes) are most commonly associated with forested habitats in Africa, there are several countries in both West and East Africa where chimpanzee populations inhabit savannas. This implies that the <a href="https://www.earth.com/news/illegal-cannabis-farms-infringe-on-crucial-animal-habitats/">habitats</a> are more open, with higher temperatures and lower annual rainfall, which has required different adaptive strategies from the chimpanzees living there. 



Savanna chimpanzees are taxonomically identical to forest-dwelling chimpanzees, and thus comparisons of the behavior, morphology and ecology of the two groups help researchers to understand how early humans may have adapted, millions of years ago, when African forests began to recede and be replaced by open savannas.&nbsp;



Certain behaviors and physiological responses in savanna chimpanzees, such as resting in caves or digging to access water, are considered specific adaptations to life in savanna habitats and are not observed in their forest-dwelling counterparts.&nbsp;



Adriana Hernández, Serra Hunter professor at the Faculty of Psychology of the University of Barcelona, co-led a recent study conducted by an international team of primatologists that reviewed the existing research on the behavior and ecology of savanna chimpanzees to understand how these apes adapt to extreme conditions.



“The study on savanna chimpanzees and what we call the&nbsp;landscape savanna effect&nbsp;have important implications for reconstructing the behavior of the first hominins who lived in similar habitats and therefore, it helps us to better understand our own evolution,” said Professor Hernández, who co-led the study with Stacy Lindshield from the University of Purdue.



"We know that early hominins adapted to savanna environments similar to those occupied by chimpanzees today, and researchers think that savanna conditions caused adaptations in our ancestors, such as brain expansion or tolerance to high temperatures."



“Therefore, understanding how our genetically closest living relatives adapt to a dry, hot, seasonal and open environment, very similar to those where early hominins lived, helps us to model how our ancestors might have adapted and how the features that define us as humans might have emerged.”



Chimpanzees share 98.7 percent of their DNA with humans and have a common ancestor that lived between 4.5 and 6 million years ago. This makes them the closest living relatives of modern humans. However, they lack some of the physiological and cultural traits that help humans adapt to extreme heat, such as numerous sweat glands, relative lack of hair and the ability to fashion water containers in which to carry or store water.&nbsp;



The researchers found that savanna chimpanzees have developed specific strategies to help them cope with high temperatures.&nbsp;



“Understanding how they deal with heat can help us better understand what strategies human ancestors may have used to cope with high temperatures. Some strategies are probably the same for chimpanzees and hominins, such as the use of caves or going into water pools to cool down,” noted Professor Hernández. They also try to hydrate themselves during the advanced dry season by digging for water in certain places. “Early hominins also had to deal with low water availability during part of the year."



The study also found that chimpanzee social groups in the savanna have unusually large home ranges of around 100 km², whereas chimpanzees living in more forested areas have ranges between 3 and 30 km². "However, although group sizes are similar in different habitats, chimpanzees in the savanna have a much lower population density, which could be explained by the low availability of food in this habitat."



It is thought that there are fewer chimpanzees living in savanna habitats than in forests, although the exact numbers are not known. In general, knowledge about savanna chimpanzees is incomplete and much more research is needed.&nbsp;



"It should be noted that there are far fewer sites where savanna chimpanzees have been studied, as there are only two study sites where savanna chimpanzees are habituated to humans and their behavior can be observed directly. In contrast, there are many study sites where chimpanzees are fully habituated to researchers in the forest, a habitat where these primates have been studied for decades," explained Professor Hernández.



This study also makes a contribution to understanding the potential effects of climate change on forest chimpanzees, in particular. "The adaptation of savanna chimpanzees to extreme climates can help us model how chimpanzees that currently inhabit forests might adapt to changes that climate studies project will make their environments drier and warmer," said the researchers.



"This is important, since the species is categorized as Endangered and the West African subspecies (Pan troglodytes verus) is Critically Endangered."



The study is published in the journal&nbsp;<a href="https://onlinelibrary.wiley.com/journal/15206505">Evolutionary Anthropology</a>.



---



By <a href="mailto:bosman@truewan.co.za">Alison Bosman</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Chimpanzees give us clues about early human evolution

Although chimpanzees (Pan troglodytes) are most commonly associated with forested...

In evolution, it’s usually thought that organisms avoid competition through resource partitioning, which allows a greater diversity of organisms than otherwise possible. For instance, if two birds live in the same <a href="https://www.earth.com/news/old-oak-trees-ramp-up-photosynthesis-in-response-to-rising-co2/">tree</a> and eat the same types of insects, one bird may specialize in the top of the tree while the other specializes in the bottom of the tree. This works with plants as well as animals and other organisms.&nbsp;



In a new report from <a href="http://www.okayama-u.ac.jp/index_e.html">Okayama University</a>,&nbsp; researchers suggest that resource partitioning is not always necessary for plants to coexist. A theory called the “pre-emptive selfing hypothesis” proposes that if plants can evolve self pollination, they may be able to coexist without resource partitioning. To validate their theory, the Japanese scientists used mathematical modeling and computer simulations.&nbsp;



The model simulated individual-based scenarios to look at the conditions where evolution favored selfing, or self pollination, in the face of competition with other plants.&nbsp;



"In a previous study, we found that two species of Asian dayflower, Commelina communis and C. communis f. ciliata, have flowers that look similar, share the same pollinators, and compete through pollinator-mediated reproductive interference. However, this observation had no explanation in the existing theory," said lead researcher Dr. Koki R. Katsuhara.



"Then I hit upon the pre-emptive selfing hypothesis that offered a plausible explanation for their existence and figured that this idea might apply to plant species other than Commelina."



The study shows that the evolutionary mechanism of coexistence between similar species of flowering plants is more complex than previously understood. It also shows that coexistence of two plants even within the same ecological niche is possible.&nbsp;



"This work will lead to an improved understanding of plant species coexistence, which, in turn, could help us manage plant diversity in a sustainable way, as well as rescue native species threatened by an invasive alien species," said Dr. Katsuhara.



The study is published in the <a href="https://www.britishecologicalsociety.org/publications/journals/journal-of-ecology/">Journal of Ecology</a>.



---By <a href="mailto:zachfitzner@yahoo.com">Zach Fitzner</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

When faced with competition, some plants learn to self-pollinate

In evolution, it’s usually thought that organisms avoid competition through...

There has been much debate and hypothesizing about the origins of <a href="https://www.earth.com/news/domestication-shrunk-rabbits-brains/">domestication</a> in horses (Equus caballus). Where were they first domesticated, and by whom? How did they spread around the globe and what were their ancestors like? Many previous studies have attempted to answer these questions but no final resolution has been forthcoming, and the early domestication of the horse has remained exceedingly difficult to trace in the archeological record.&nbsp;



In a new study led by Professor Ludovic Orlando of <a href="https://www.cnrs.fr/">CNRS</a>, a team of 162 international scientists has had a breakthrough. The experts, who specialize in archeology, paleogenetics and linguistics used the modern technologies of genetic analysis.&nbsp;



In recent years, a scientific consensus had emerged linking the Botai culture of northern Kazakhstan with the first domestication of horses, based on the presence of 5,500-year-old skeletal remains with damage to the dentition that is commonly linked to the use of bridle mouthpieces. However, when Ludovic Orlando's team looked at the DNA from the archeological remains, they found that the animals were Przewalsky’s horses (Equus przewalski), a totally different species from modern domesticated horses.&nbsp;



In all other locations hypothesized to be potential foci for domestication, for example Anatolia, Siberia and the Iberian Peninsula, the evidence turned out to be false. “We knew that the time period between 4,000 to 6,000 years ago was critical but no smoking guns could ever be found,” said Professor Orlando.&nbsp;



The scientific team thus decided to extend their study and analyze the genomes of 273 horses that lived between 50,000 and 200 years BC, at sites throughout Eurasia. This information was sequenced at the Centre for Anthropobiology and Genomics of Toulouse (CNRS/Université Toulouse III – Paul Sabatier) and Genoscope&nbsp;(CNRS/CEA/Université d’Évry) before being compared with the genomes of modern domestic horses.



The results indicated that, although Eurasia was once populated by genetically distinct horse populations, a dramatic change occurred between 2000 and 2200 BC. “That was a chance: the horses living in Anatolia, Europe, Central Asia and Siberia used to be genetically quite distinct,” explained study first author Dr. Pablo Librado. 



Then, a single genetic profile, previously found only on the Pontic steppes (North Caucasus), began to spread beyond its native region, replacing all the wild horse populations from the Atlantic to Mongolia. From this the authors conclude that horses were first domesticated in the Pontic-Caspian steppes,&nbsp;northern Caucasus, before spreading out through the rest of Eurasia within a few centuries.&nbsp;



“The genetic data also point to an explosive demography at the time, with no equivalent in the last 100,000 years,” said Professor Orlando. “This is when we took control over the reproduction of the animal and produced them in astronomic numbers.”



Two striking differences were found in the genome of this horse that spread so rapidly throughout Eurasia: the new horses had more docile behavior and stronger backbones than the breeds they replaced. The researchers suggest that these characteristics ensured the animals’ success at a time when horse travel was becoming more commonplace and widespread.



Indeed, the research also showed that the genetically different horse spread throughout Asia at the same time as spoke-wheeled chariots and Indo-Iranian languages. However, the migrations of Indo-European populations, from the steppes to Europe during the third millennium BC&nbsp;could not have been based on the horse, as its domestication and diffusion came later. This demonstrates the importance of incorporating the history of animals when studying human migrations and encounters between cultures, state the authors.



The study is published in the journal <a href="https://www.nature.com/">Nature</a>.



---



By <a href="mailto:bosman@truewan.co.za">Alison Bosman</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

The origin of horse domestication has finally been revealed

There has been much debate and hypothesizing about the origins...

<div id="58e3ebce955a315103d39bd1" class="vdb_player vdb_58e3ebce955a315103d39bd158d96b98cd4fed198a0d2a49" vdb_params="m.embeded=cms_video_plugin_www.earth.com" data-placeholder="//img.vidible.tv/prod/2018-11/21/5bf514888215763a9c1fc1a9/5bf5149ed2434500019577cd_1920x1080_FES_v1.jpg?w=5760&#038;h=3600&#038;q=60">
 <script type="text/javascript" src="//delivery.vidible.tv/jsonp/pid=58e3ebce955a315103d39bd1/vid=5bf514888215763a9c1fc1a9/58d96b98cd4fed198a0d2a49.js?m.embeded=cms_video_plugin_www.earth.com"></script>
 </div>
  
Today&#8217;s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> introduces a new tool called the Electronic Field Book, software that was designed to help scientists overcome the challenge of poor connections in remote locations. 

The device integrates data sharing, voice chat, and real-world positioning with inputs from external tools such as microscopes and spectrometers. 

This innovative tool can record every step of a scientific research expedition while documenting all communication. 

An upgraded version of the Electronic Field Book was used for the first time during the Pangaea 2018 campaign in Lanzarote, Spain. 

&#8212; 

By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer 

Video Credit: European Space Agency

The Electronic Field Book will revolutionize research expeditions