Did Land Plants Evolve from Algae?

A botanist critiques the
latest evolutionary claim about
plants that conquered the land

In Germany, evolutionary biologists have imagined that land plants evolved from green algae.

Professor Jan de Vries, Göttingen University, who led the research, explains: “One of the big surprises was that we found several highly connected genes – known as ‘hubs’ – in the network shared by these very different organisms that actually split from each other in evolutionary terms around 600 million years ago. These hubs appear to bundle information and shape the overall network response.”

We asked botanist Dr Margaret Helder for her impressions about this claim.

Q: Dr Helder, scientists at the University of Gottingen recently claimed that “The closest algal relatives of land plants are the filamentous and unicellular conjugating algae, the zygnematophytes.” What are your thoughts about this claim?

Zygnema, an alga claimed to be the ancestor of land plants

A: If you look at the pictures of the moss and the alga, you might ask why did they pick the Zygnemataceae upon which to base their theories of invasion of the land. The zygnemataceae are nothing like what one might like for an ancestor of the land plants. Their cells are surrounded by a mucilaginous sheath, they are completely without any branching and they have absolutely no flagellated motile cells like the zoospores and gametes that other green algae exhibit and which all the “lower” land plants exhibit.

Q: The researchers say they found “a shared stress response network” between algae and plants that they believe last had a common ancestor 600 million years ago. Does that constitute good evidence?

A: What they do exhibit presumably is some similarities in DNA sequences. There are many green algae which exhibit morphological similarities to the presumed ancestors of the land, and pre-DNA evolutionary scenarios were all based on one or other of these filamentous and branched green algae.

Q: What are some of the other major differences between these algae and land plants?

Physcomitrium, a moss, a land plant.

A: The conjugation (sexual combination) in the Zygnemataceae is completely unlike anything seen in other green algae or land plants. Among the green algae, these are the least likely candidates for ancestors of the land plants. People concentrating on DNA and biochemical properties, possibly do not know about the extreme difficulties of explaining how the Zygnemataceae came to invade the land.

Q: Why do you think researchers are so focused on connecting such very different organisms by evolution?

A: The study about the relationships between the Zygnemataceae algae and mosses (resembling presumably the plants invading the land) is certainly interesting. I consider this topic a particularly clear case of people fooling themselves in order to support an evolutionary scenario.

Margaret Helder completed her education with a Ph.D. in Botany from Western University in London, Ontario (Canada). She was hired as Assistant Professor in Biosciences at Brock University in St. Catharines, Ontario. Coming to Alberta in 1977, Dr Helder was an expert witness for the State of Arkansas, December 1981, during the creation/evolution ‘balanced treatment’ trial. She served as member of the editorial board of Occasional Papers of the Baraminology Study Group in 2001. She also lectured once or twice a year (upon invitation) in scheduled classes at University of Alberta (St. Joseph’s College) from 1998-2012. Her technical publications include articles in the Canadian Journal of Botany, chapter 19 in Recent Advances in Aquatic Mycology (E. B. Gareth Jones. Editor. 1976), and most recently she authored No Christian Silence on Science (2016) which promotes critical evaluation of scientific claims. She is married to John Helder and they have six adult children.