Month: September 2022

COEVOLUTION. "Angiosperms and their insect pollinators have flourished with extraordinary diversity through parallel and successive "explosive" radiations over the past 140 million years. It has been suggested that the intimate relationships between flowering plants and their pollinators have fuelled each other's diversification." https://lnkd.in/ePD6mWn View in LinkedIn

INDEPENDENT EVOLUTIONARY PATH. "During higher plant evolution, plants drastically increased the complexity of their bodies, with recent angiosperms representing the most evolved plants. It seems that the first roots, shoots, and leaves evolved together with the evolution of the first xylem and phloem elements, representing the vascular system. Roots and shoots, as well as vascular elements, followed an independent evolutionary path in vascular plants." https://lnkd.in/eDvT22D View in LinkedIn

CLIMATIC EVOLUTION. "The Early Cretaceous configuration (120 Ma) appears as pivotal, with the global onset of new climatic conditions (higher rainfall and temperatures) which can favor macroevolutionary changes in the flora, such as angiosperm diversification." https://lnkd.in/eiM6qET View in LinkedIn

VAST STRUCTURAL DIVERSITY. "Flowers, the reproductive organs of angiosperms, are more varied than the equivalent structures of any other group of organisms. Because of this variation, interest in plant sexual diversity has a long and venerable history in biology. However, despite this attention, it is still not obvious why flowering plants have evolved such extraordinarily diverse means to achieve only one primary function — mating success." https://lnkd.in/eSndawa View in LinkedIn

"THE EVOLUTION of seed plants and later angiosperms appears to be the result of two distinct rounds of whole genome duplication events. These occurred at 319 million years ago and 192 million years ago. Another possible whole genome duplication event at 160 million years ago perhaps created the ancestral line that led to all modern flowering plants." https://lnkd.in/en2Nbzs View in LinkedIn

SO ENDS this first weekend in flowering plants and their rapid emergence and domination of the plant world. Due to the innovation of flowers, their co-evolution with pollinating insects, and other structural modifications of their forms, this group of plants was able to diversify rapidly. A flower is not just a flower. It is an historical testament to complex co-evolution and innovation. View in LinkedIn

"MICHAEL LYNCH once wrote, “Nothing in evolution makes sense except in the light of population genetics” (Distinguished professor of biology, Indiana University). http://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1004351 View in LinkedIn

FIXATION BY DRIFT. "What is underappreciated by many nonevolution specialists is that much of molecular evolution in eukaryotes is primarily the result of genetic drift, or the fixation of neutral mutations. This view has been widely appreciated by molecular evolutionary biologists for the past 35 years." http://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1004351 View in LinkedIn

FITNESS LOAD. "Although mutations provide the ultimate material upon which natural selection depends, most mutations are deleterious, and in certain settings can lead to a substantial fitness load. We are attempting to understand the nearly 1000-fold range of variation in the mutation rate that exists across the Tree of Life, through the study of a diversity of invertebrates and unicellular eukaryotes and prokaryotes." (Michael Lynch). https://lnkd.in/e8G48jD View in LinkedIn

GENETIC DRIFT. "We are promoting the idea that the power of random genetic drift imposes a lower bound to the degree to which natural selection can reduce the mutation rate. This drift-barrier hypothesis seems to support a number of previously disconnected observations, including the increase in the mutation rate with reductions in effective population size, the magnified error rates associated with DNA polymerases and repair enzymes used only infrequently in replication, and the extraordinarily high rates of base misincorporation into transcripts." (Michael Lynch). https://lnkd.in/e8G48jD View in LinkedIn