Featured Research

from universities, journals, and other organizations

What Are The Odds Of Finding Extraterrestrial Intelligent Life?

Date:
April 19, 2008
Source:
University of East Anglia
Summary:
A mathematical model suggests that the odds of finding new life on other Earth-like planets are low, given the time it has taken for beings such as humans to evolve and the remaining life span of the Earth. Structurally complex and intelligent life evolved late on Earth and it has already been suggested that this process might be governed by a small number of very difficult evolutionary steps.

Telescope image of the nearby spiral galaxy M74. Is there anybody out there?
Credit: NASA, ESA, and the Hubble Heritage (STScI/AURA)-ESA/Hubble Collaboration

Is there anybody out there? Probably not, according to a scientist from the University of East Anglia. A mathematical model produced by Prof Andrew Watson suggests that the odds of finding new life on other Earth-like planets are low, given the time it has taken for beings such as humans to evolve and the remaining life span of Earth.

Related Articles


Structurally complex and intelligent life evolved late on Earth and it has already been suggested that this process might be governed by a small number of very difficult evolutionary steps.

Prof Watson, from the School of Environmental Sciences, takes this idea further by looking at the probability of each of these critical steps occurring in relation to the life span of Earth, giving an improved mathematical model for the evolution of intelligent life.

According to Prof Watson a limit to evolution is the habitability of Earth, and any other Earth-like planets, which will end as the sun brightens. Solar models predict that the brightness of the sun is increasing, while temperature models suggest that because of this the future life span of Earth will be ‘only’ about another billion years, a short time compared to the four billion years since life first appeared on the planet.

“The Earth’s biosphere is now in its old age and this has implications for our understanding of the likelihood of complex life and intelligence arising on any given planet,” said Prof Watson.

“At present, Earth is the only example we have of a planet with life. If we learned the planet would be habitable for a set period and that we had evolved early in this period, then even with a sample of one, we’d suspect that evolution from simple to complex and intelligent life was quite likely to occur. By contrast, we now believe that we evolved late in the habitable period, and this suggests that our evolution is rather unlikely. In fact, the timing of events is consistent with it being very rare indeed.”

Prof Watson suggests the number of evolutionary steps needed to create intelligent life, in the case of humans, is four. These probably include the emergence of single-celled bacteria, complex cells, specialized cells allowing complex life forms, and intelligent life with an established language.

“Complex life is separated from the simplest life forms by several very unlikely steps and therefore will be much less common. Intelligence is one step further, so it is much less common still,” said Prof Watson.

His model, published in the journal Astrobiology, suggests an upper limit for the probability of each step occurring is 10 per cent or less, so the chances of intelligent life emerging is low – less than 0.01 per cent over four billion years.

Each step is independent of the other and can only take place after the previous steps in the sequence have occurred. They tend to be evenly spaced through Earth’s history and this is consistent with some of the major transitions identified in the evolution of life on Earth.


Story Source:

The above story is based on materials provided by University of East Anglia. Note: Materials may be edited for content and length.


Cite This Page:

University of East Anglia. "What Are The Odds Of Finding Extraterrestrial Intelligent Life?." ScienceDaily. ScienceDaily, 19 April 2008. <www.sciencedaily.com/releases/2008/04/080416110124.htm>.
University of East Anglia. (2008, April 19). What Are The Odds Of Finding Extraterrestrial Intelligent Life?. ScienceDaily. Retrieved November 28, 2014 from www.sciencedaily.com/releases/2008/04/080416110124.htm
University of East Anglia. "What Are The Odds Of Finding Extraterrestrial Intelligent Life?." ScienceDaily. www.sciencedaily.com/releases/2008/04/080416110124.htm (accessed November 28, 2014).

Share This


More From ScienceDaily



More Fossils & Ruins News

Friday, November 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

New Dinosaur Species Found in Museum Collection

New Dinosaur Species Found in Museum Collection

Reuters - Innovations Video Online (Nov. 27, 2014) A British palaeontologist has discovered a new species of dinosaur while studying fossils in a Canadian museum. Pentaceratops aquilonius was related to Triceratops and lived at the end of the Cretaceous Period, around 75 million years ago. Jim Drury has more. Video provided by Reuters
Powered by NewsLook.com
Classic Hollywood Memorabilia Goes Under the Hammer

Classic Hollywood Memorabilia Goes Under the Hammer

Reuters - Entertainment Video Online (Nov. 26, 2014) The iconic piano from "Casablanca" and the Cowardly Lion suit from "The Wizard of Oz" fetch millions at auction. Sara Hemrajani reports. Video provided by Reuters
Powered by NewsLook.com
3D Map of Antarctic Sea Ice to Shed Light on Climate Change

3D Map of Antarctic Sea Ice to Shed Light on Climate Change

Reuters - Innovations Video Online (Nov. 24, 2014) A multinational group of scientists have released the first ever detailed, high-resolution 3-D maps of Antarctic sea ice. Using an underwater robot equipped with sonar, the researchers mapped the underside of a massive area of sea ice to gauge the impact of climate change. Ben Gruber reports. Video provided by Reuters
Powered by NewsLook.com
Ruins Thought To Be Port Actually Buried Greek City

Ruins Thought To Be Port Actually Buried Greek City

Newsy (Nov. 24, 2014) Media is calling it an "underwater Pompeii." Researchers have found ruins off the coast of Delos. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins