Zoonomia Project Explains Connection between Humans, Mammals

Scientists are studying the genetic¹ information of different animals that could help them learn more about human life. They are discovering qualities shared among different species.

One of the main findings they report is that certain areas of genetic information have stayed the same throughout evolution.

The scientists are part of an international effort called the Zoonomia Project. Eleven papers about the research appeared in the recent issue of the publication Science. The Zoonomia team is led by Elinor Karlsson and Kerstin Lindblad-Toh at the Broad Institute of MIT and Harvard.

The studies offer understanding of human qualities and diseases and animal abilities, like hibernation². It even includes genetic information about Balto, a sled dog who helped save lives in Alaska in the year 1925.

Scientists looked at 240 species of mammals. They sequenced and compared the species' genomes or the "instructions" that organisms need to grow and operate.

Lindblad-Toh teaches comparative genomics at the Uppsala University in Sweden. She said, "The human genome was sequenced more than 20 years ago and, despite that, it's still really hard to understand what the functional³ elements are."

The scientists found 4,552 genomic elements that are the same across mammal species and were identical in 235 of the 240 species. Some elements have stayed the same for millions of years of evolution. At least 10 percent of the human genome is mostly unchanged across the species, one study found.

Certain genes⁴ help create proteins. These proteins control the functions of cells, which is the main purpose of DNA⁵. The areas of the genome that is unchanged occurs outside of these one percent of genes.

The theory is that these unchanged parts might serve a purpose and may be "regulatory elements." These elements contain commands directing how much protein is produced and where and when it is produced.

Matthew Christmas is an evolution genetics expert at the Uppsala University and a lead writer of one of the published studies.

"Many of these elements are located close to genes involved in embryo⁶ development - a process that needs to be tightly controlled if it is to result in the development of a healthy" and functional animal.

Scientists found more than three million of these regulatory elements in the human genome. Almost half of these were not known before.

They also focused on changes within animals. Scientists looked at the genetic sequences of certain species and compared them with their ancestors.

Karlsson said that some species saw many changes over a short time in connection with change to their environments.

Hibernation is one example. The findings on hibernation genetics could help with human therapies, intensive care and even space flight.

"One of the really cool things about mammals is that at this point in time, they've basically adapted to survive in nearly every single ecosystem⁷ on Earth," Karlsson said.

The Zoonomia studies have even shown how different mammals' sense of smell differs. Mammals like the African savanna⁸ elephant and the two-toed sloth⁹ have a very sharp sense of smell. Whales and dolphins have almost no sense of smell, while humans are somewhere in the middle.

Another group of scientists looked for genes that other mammals have but humans do not.

Steven Reilly is a genetics researcher at Yale University. He said that instead of focusing on new qualities that are unique to humans, they looked at what humans did not have.

"Losing pieces of DNA can actually generate new features," Reilly said.

He said that, for example, a small DNA deletion between chimpanzees and humans that occurred 6-7 million years ago caused a lot of changes in the expression of the genes.

Those changes were to the regulation of the nervous system genes.

Christmas added, "This makes sense as some of the biggest differences between us and our ape cousins are in our brain power...."

Words in This Story

species – n. a group of animals or plants that are similar and can produce young animals or plants

evolution - n. a process of slow change and development

hibernation – n. to spend the winter sleeping or resting

mammal – n. a type of animal that feeds milk to its young and

regulatory – adj. controlling an activity or process, especially by using rules

1 genetic   

adj.遗传的，遗传学的

参考例句：

• It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
• Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。

2 hibernation   

n.冬眠

参考例句：

• Bears wake up in the spring after a winter of hibernation.熊经过一个冬天的冬眠后在春季苏醒。
• The tortoise spends the winter months in hibernation.乌龟在冬眠中度过寒冬季节。

3 functional   

adj.为实用而设计的，具备功能的，起作用的

参考例句：

• The telephone was out of order,but is functional now.电话刚才坏了，但现在可以用了。
• The furniture is not fancy,just functional.这些家具不是摆着好看的，只是为了实用。

4 genes   

n.基因( gene的名词复数 )

参考例句：

• You have good genes from your parents, so you should live a long time. 你从父母那儿获得优良的基因，所以能够活得很长。 来自《简明英汉词典》
• Differences will help to reveal the functions of the genes. 它们间的差异将会帮助我们揭开基因多种功能。 来自英汉非文学 - 生命科学 - 生物技术的世纪

5 DNA   

(缩)deoxyribonucleic acid 脱氧核糖核酸

参考例句：

• DNA is stored in the nucleus of a cell.脱氧核糖核酸储存于细胞的细胞核里。
• Gene mutations are alterations in the DNA code.基因突变是指DNA密码的改变。

6 embryo   

n.胚胎，萌芽的事物

参考例句：

• They are engaging in an embryo research.他们正在进行一项胚胎研究。
• The project was barely in embryo.该计划只是个雏形。

7 ecosystem   

n.生态系统

参考例句：

• This destroyed the ecosystem of the island.这样破坏了岛上的生态系统。
• We all have an interest in maintaining the integrity of the ecosystem.维持生态系统的完整是我们共同的利益。

8 savanna   

n.大草原

参考例句：

• The savanna is also the home of meat-eaters--the lion,leopard,and hyena who feed on the grasseaters.大草原也是食肉动物的家乡--狮子、豹、鬣狗--它们都是以草食动物维持生命的。
• They sped upon velvet wheels across an exhilarant savanna.他们的马车轻捷地穿过一片令人赏心悦目的大草原。

9 sloth   

n.[动]树懒；懒惰，懒散

参考例句：

• Absence of competition makes for sloth.没有竞争会导致懒惰。
• The sloth spends most of its time hanging upside down from the branches.大部分时间里树懒都是倒挂在树枝上。