Plants evolved complexity in two bursts -- with a 250-million-year hiatus

Lena Vermette

10/18/21

Stanford University. "Plants evolved complexity in two bursts -- with a 250-million-year hiatus." ScienceDaily. ScienceDaily, 16 September 2021. <www.sciencedaily.com/releases/2021/09/210916142851.htm> 

According to Stanford University in the article "Plants evolved complexity in two bursts -- with a 250-million-year hiatus" there has been a recent discovery that leads scientists to believe there were two major phases of plant diversification counter to the previously believed theory that plants slowly evolved over millions of years. These two phases were when plants first developed a reproduction system through seeds, and when the plants developed the ability to have flowers and bloom. The article begins by stating that many scientists had previously formed a theory to match this discovery, although before there was no evidence to support the claim. Stanford tells the reader, “While scientists have long assumed that plants became more complex with the advent of seeds and flowers, the new findings, published Sept. 17 in Science, offer insight to the timing and magnitude of those changes” This article does not go into depth about the new findings but explains their impact on the scientific world. The article goes on to talk about how, “This complexity [of flowers] makes it difficult for scientists to compare flowering plants to plants with simpler reproductive systems, such as ferns or some conifers” Stanford explains that earlier in history there were normally parallel studies conducted regarding flowering plants and nonflowering plants because it was difficult to compare them with each other because of their many differences. Later on, scientists were able to conduct combined studies because they found a method of comparing the two types of plants. This involves dissecting the plant’s reproductive parts and noting how many different parts are within each plant. The article concludes by talking about the correlations between the development of plants and animals throughout different time periods. An example of this is when Stanford explains that the major stage of evolution for animals took place before the major stage of evolution for plants did, “After the Devonian, huge changes occurred in the animal kingdom… but plants didn't see a major change in reproductive complexity until they developed flowers” This is important to note because while the evolution of the two groups depended on each other, they did not happen simultaneously as one might assume without knowledge to the contrary.

This article is extremely relevant to society; in fact, the existence of it. Without the diversification of plants, there wouldn’t be enough variety of plants to feed a large population of animals. Many of the herbivores wouldn’t survive from lack of food which would provide a less prominent food source for the other animals which would lower their population as well. Being omnivores, humans would be impacted by both these issues. Humans wouldn’t have enough plant-based food to thrive on that they would start depending on mainly a meat diet which would slowly dwindle away because the animals would be experiencing the same dilemma as the humans. Here the article claims that, “When land plants first diversified… Earth was... devoid of trees or terrestrial vertebrate animals” This means that even after the first diversification of plants, the plants were unable to support land animals with a spine, such as humans. This is why humans had not yet evolved. Knowing that there is a correlation between the second growth of more complex plants and the existence of humans explains why this event is so notable when discussing human society today. None of this would be possible without the plants that impact the entirety of our food source and allow our community to stay well-nourished and thrive.

One successful tactic the author used when writing this article was including the valuable detail of how plants are classified based on their complexity. As this is not a well-known concept, the reader would not have a full understanding without knowing what makes one plant more complex than another. Here it is mentioned that the complexity of a plant is based upon its reproductive system, “The research uses a novel but simple metric to classify plant complexity based on the arrangement and number of basic parts in their reproductive structures” Since the entire article is about how plants have evolved over time to be more complex, it was a smart decision by the author to include this explanation. On the other hand, the author neglected to include a different detail that would have significantly improved the article. The reason for the first major diversification was provided while there was nothing mentioned regarding the cause of the second wave, “When land plants first diversified in the early Devonian about 420 million to 360 million years ago, Earth was a warmer world devoid of trees or terrestrial vertebrate animals” The earth’s increase in temperature explained the new sprout of life in the plant world. Later on the reader would expect a reason for the second large change in plants because this was the more significant out of the two diversifications, unfortunately, this cause never did come. Instead, there is a massive amount of information about the discovery and classification of different plants; some that flowers and others that don’t. This information is significant, however, it does not take precedence over the reason that caused all of these discoveries to be possible. This article would have been far more informative if it mentioned how and why certain plants developed the ability to bloom, simultaneously increasing the complexity of their systems.