密歇根新闻广播 城市如何推动我们生活中的生物进化

Cities are creating new ecosystems¹, and they're changing the way some creatures evolve. Those are the findings of a new paper in the journal Science.

Jason Munshi-South is an author of the paper and an associate professor of biological sciences at Fordham University. He and his co-author, Marc Johnson, reviewed more than 190 studies that have documented how cities drive evolution of mammals, plants, birds and insects.

"We found there's actually now an overwhelming surge of evidence just in the last five to 10 years that a myriad² of species are evolving in cities," he says.

Munshi-South says a number of factors are driving this.

"Perhaps one of the most obvious and distinct factors that can be measured is the built environment. So you have a number of species that now are kind of trapped in little islands within cities, in places like city parks or other green spaces, and they may just differentiate³ from one another over time," he explains.

He says species can accrue⁴ differences over generations, and some native species have adapted to live successfully in cities.

"One of my favorite examples is work by Kristin Winchell, who's a graduate student at the University of Massachusetts-Boston, and she's found that several populations of lizards⁵ in Puerto Rico have shown heritable changes in their limbs that allow them to better survive when they're living in built environments, like crawling around on walls and fence posts and things like that, instead of on natural vegetation, like trees and bushes," he says.

Eating from the same table

But pests and diseases have also rapidly adapted to city life. Munshi-South says pests have undergone at least two major waves of evolution.

"The first wave would've been early on, when humans began settling in dense⁶, agricultural villages and towns. That's when you saw the evolution of a lot of these commensal pests... that literally⁷ means ‘eating from the same table,'" he says.

These animals evolved to subsist⁸ on food provided by people: stealing leftover⁹ grain, or food inside people's houses.

He says in the last several decades, we've seen a second wave of evolution of these pests living in cities, for example, as species become resistant¹⁰ to pesticides¹¹.

"They also show interesting genetic¹² structure depending on how humans move them around from city to city. You can trace their history of movement around the world using genetic analyses that show serial¹³ evolution as they went from one city to another," he explains.

And he says you can see those changes even within a city – with pests like bedbugs and cockroaches¹⁴.

"You can see very different populations even in buildings that are next to one another, because the original infestation¹⁵ came from different places, sometimes even from different cities in other countries," he says.

Munshi-South says it's hard to know what the implications of all these changes are.

"We're not guiding the process, this is basically happening with us ignorant of the process until we start doing the studies. So many of these examples we've documented are just species finding a way to survive and thrive in urban environments," he says.

"Another thing that makes this difficult to predict is that you have a number of species that occur in cities that don't occur together other places in nature. So cities can be very unique ecosystems with many new interactions between species. And so that will create, basically, new ecology that will feed back onto the evolution of these populations."

He says one thing we can do to help native species in cities is design connections between green spaces, so creatures don't become isolated¹⁶ in little pockets.

1 ecosystems   

n.生态系统( ecosystem的名词复数 )

参考例句：

• There are highly sensitive and delicately balanced ecosystems in the forest. 森林里有高度敏感、灵敏平衡的各种生态系统。 来自《简明英汉词典》
• Madagascar's ecosystems range from rainforest to semi-desert. 马达加斯加生态系统类型多样，从雨林到半荒漠等不一而足。 来自辞典例句

2 myriad   

adj.无数的；n.无数，极大数量

参考例句：

• They offered no solution for all our myriad problems.对于我们数不清的问题他们束手无策。
• I had three weeks to make a myriad of arrangements.我花了三个星期做大量准备工作。

3 differentiate   

vi.(between)区分；vt.区别；使不同

参考例句：

• You can differentiate between the houses by the shape of their chimneys.你可以凭借烟囱形状的不同来区分这两幢房子。
• He never learned to differentiate between good and evil.他从未学会分辨善恶。

4 accrue   

v.(利息等)增大，增多

参考例句：

• Ability to think will accrue to you from good habits of study.思考能力将因良好的学习习惯而自然增强。
• Money deposited in banks will accrue to us with interest.钱存在银行，利息自生。

5 lizards   

n.蜥蜴( lizard的名词复数 )

参考例句：

• Nothing lives in Pompeii except crickets and beetles and lizards. 在庞培城里除了蟋蟀、甲壳虫和蜥蜴外，没有别的生物。 来自辞典例句
• Can lizards reproduce their tails? 蜥蜴的尾巴断了以后能再生吗？ 来自辞典例句

6 dense   

a.密集的，稠密的，浓密的；密度大的

参考例句：

• The general ambushed his troops in the dense woods. 将军把部队埋伏在浓密的树林里。
• The path was completely covered by the dense foliage. 小路被树叶厚厚地盖了一层。

7 literally   

adv.照字面意义，逐字地；确实

参考例句：

• He translated the passage literally.他逐字逐句地翻译这段文字。
• Sometimes she would not sit down till she was literally faint.有时候，她不走到真正要昏厥了，决不肯坐下来。

8 subsist   

vi.生存，存在，供养

参考例句：

• We are unable to subsist without air and water.没有空气和水我们就活不下去。
• He could subsist on bark and grass roots in the isolated island.在荒岛上他只能靠树皮和草根维持生命。

9 leftover   

n.剩货，残留物，剩饭；adj.残余的

参考例句：

• These narrow roads are a leftover from the days of horse-drawn carriages.这些小道是从马车时代沿用下来的。
• Wonder if that bakery lets us take leftover home.不知道那家糕饼店会不会让我们把卖剩的带回家。

10 resistant   

adj.(to)抵抗的，有抵抗力的

参考例句：

• Many pests are resistant to the insecticide.许多害虫对这种杀虫剂有抵抗力。
• They imposed their government by force on the resistant population.他们以武力把自己的统治强加在持反抗态度的人民头上。

11 pesticides   

n.杀虫剂( pesticide的名词复数 )；除害药物

参考例句：

• vegetables grown without the use of pesticides 未用杀虫剂种植的蔬菜
• There is a lot of concern over the amount of herbicides and pesticides used in farming. 人们对农业上灭草剂和杀虫剂的用量非常担忧。 来自《简明英汉词典》

12 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。

13 serial   

n.连本影片，连本电视节目；adj.连续的

参考例句：

• A new serial is starting on television tonight.今晚电视开播一部新的电视连续剧。
• Can you account for the serial failures in our experiment?你能解释我们实验屡屡失败的原因吗？

14 cockroaches   

n.蟑螂( cockroach的名词复数 )

参考例句：

• At night, the cockroaches filled the house with their rustlings. 夜里，屋里尽是蟑螂窸窸瑟瑟的声音。 来自辞典例句
• It loves cockroaches, and can keep a house clear of these hated insects. 它们好食蟑螂，可以使住宅免除这些讨厌昆虫的骚扰。 来自百科语句

15 infestation   

n.侵扰，蔓延

参考例句：

• The premises were treated for cockroach infestation.因蟑螂成灾，这些房屋集中进行了灭蟑活动。
• Parts of California are suffering from an infestation of oriental fruit flies.加利福尼亚的部分地区正遭受东方果蝇的大肆侵袭。

16 isolated   

adj.与世隔绝的

参考例句：

• His bad behaviour was just an isolated incident. 他的不良行为只是个别事件。
• Patients with the disease should be isolated. 这种病的患者应予以隔离。