Featured Research

from universities, journals, and other organizations

Scientists Unravel Ancient Evolutionary History Of Photosynthesis

Date:
September 18, 2000
Source:
Indiana University
Summary:
All life on Earth depends on photosynthesis for food and oxygen. The origin of this crucial process in green plants is a longstanding problem in biology, and a number of different theories have been proposed to explain it. But there has been no clear evidence to support any of these theories

BLOOMINGTON, Ind. -- All life on Earth depends on photosynthesis for food and oxygen. The origin of this crucial process in green plants is a longstanding problem in biology, and a number of different theories have been proposed to explain it. But there has been no clear evidence to support any of these theories.

Related Articles


In a paper in the Sept. 8 issue of the journal Science, a team of biologists lead by Carl E. Bauer, Clyde Culbertson Professor of Biology at Indiana University, reports the results of their study of the evolution of photosynthesis.

In photosynthesis, green plants use the energy of sunlight to convert carbon dioxide into hydrocarbons that promote plant growth while generating oxygen from water and releasing the oxygen to the atmosphere. All animals including humans depend either directly or indirectly on this source of food and oxygen. Consequently, photosynthesis is considered the most important chemical process on Earth.

Scientists agree that photosynthesis originated in bacteria, with some bacteria containing photosystems that release oxygen in a way very similar to that found in green plants today, and some other bacteria containing simplified photosystems that do not release oxygen. What was not clear is which species of bacteria contains the most ancient photosystem and how photosynthesis in green plants evolved from photosynthesis in bacteria.

By generating a large new molecular data set, Bauer's group, which includes IU postdoctoral fellow Jin Xiong and IU doctoral student William Fischer, has determined that non-oxygen-producing bacterial species such as the purple and green bacteria are the most ancient photosynthetic bacteria. Another group of non-oxygen-producing bacteria known as heliobacteria evolved later.

The scientists also found that heliobacteria are the most closely related to the common ancestor of the oxygen-producing photosynthetic cyanobacteria. Cyanobacteria eventually gave rise to chloroplasts in algae and green plants, and chloroplasts are the small bodies in plant cells that carry out photosynthesis today.

The Bauer group's results reverse the conventional thinking on the evolution of photosynthetic bacteria, in which purple bacteria were considered one of the last bacterial species to evolve, not one of the first.

The Bauer group's work also reinforces recent fundamental changes in molecular genetics that show bacteria evolved in a complex manner that resembles a tangled briar patch, with branches going every which way from a number of stems, instead of a traditional evolutionary tree that shows all species neatly branching out from a single stem that represents their common ancestor, usually regarded as the universal ancestral cell. This change in perspective is necessary because gene-swapping was common among ancient bacteria early in evolution.

The work of Bauer's group demonstrates that scientists must study the evolution of individual metabolic processes such as photosynthesis rather than the evolution of entire bacterial organisms.

Bauer's Web site is at http://sunflower.bio.indiana.edu/~cbauer/bauerlab/.


Story Source:

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


Cite This Page:

Indiana University. "Scientists Unravel Ancient Evolutionary History Of Photosynthesis." ScienceDaily. ScienceDaily, 18 September 2000. <www.sciencedaily.com/releases/2000/09/000913211733.htm>.
Indiana University. (2000, September 18). Scientists Unravel Ancient Evolutionary History Of Photosynthesis. ScienceDaily. Retrieved January 26, 2015 from www.sciencedaily.com/releases/2000/09/000913211733.htm
Indiana University. "Scientists Unravel Ancient Evolutionary History Of Photosynthesis." ScienceDaily. www.sciencedaily.com/releases/2000/09/000913211733.htm (accessed January 26, 2015).

Share This


More From ScienceDaily



More Plants & Animals News

Monday, January 26, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

How To: Mixed Green Salad Topped With Camembert Cheese

How To: Mixed Green Salad Topped With Camembert Cheese

Rumble (Jan. 26, 2015) Learn how to make a mixed green salad topped with a pan-seared camembert cheese in only a minute! Music: Courtesy of Audio Network. Video provided by Rumble
Powered by NewsLook.com
Water Fleas Prepare for Space Voyage

Water Fleas Prepare for Space Voyage

Reuters - Innovations Video Online (Jan. 26, 2015) Scientists are preparing a group of water fleas for a unique voyage into space. The aquatic crustaceans, known as Daphnia, can be used as a miniature model for biomedical research, and their reproductive and swimming behaviour will be tested for signs of stress while on board the International Space Station. Jim Drury went to meet the team. Video provided by Reuters
Powered by NewsLook.com
Husky Puppy Plays With Ferret

Husky Puppy Plays With Ferret

Rumble (Jan. 26, 2015) It looks like this 2-month-old Husky puppy and the family ferret are going to be the best of friends. Look at how much fun they&apos;re having together! Credit to &apos;Vira&apos;. Video provided by Rumble
Powered by NewsLook.com
Obama's Wildlife Plan Renews Alaska Drilling Debate

Obama's Wildlife Plan Renews Alaska Drilling Debate

Newsy (Jan. 26, 2015) President Obama&apos;s proposal aims to protect more land in the Arctic National Wildlife Refuge, but so far, all that&apos;s materialized is a war of words. 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