Vestigial versions of a structure can be compared to the original version of the structure in other species to determine the homology of the structure. The homologous structures indicate a common ancestry with organisms that have a functional version of the structure. Vestigial characteristics can still be considered as adjustments, as adaptation is often defined as a property favoured by natural selection. The adjustments should therefore not be adaptive as long as they have been at some point. At least 20 years elapsed between the time Darwin designed the descent with the modification and 1859, when he revealed his ideas to the world in On the Origin of Species. During these 20 years, Darwin has done what scientists do today: he has tested his ideas on how things work with new observations and new experiments. He did so in part by imagining all sorts of objections to his own hypothesis. The use of fossil fuel calibration points (Chilopoda-Diplopoda, Xiphosura-Arachnida) or molecular calibration points (Arthropoda-Deuterostomia) did not reveal significantly different time estimates (Table 2).2. As a result, time estimates with the highest number of calibration points and proteins (average by method) were selected to summarize the difference time for each node (Table2,2, Figure 22). Fossils can also be made up of traces left by the organism during its lifetime, such as footprints or feces. These types of fossils are called trace or ichnofossil fossils, unlike body fossils.
Past life may also leave some markers that are not visible, but can be detected in the form of biochemical signals; they are called chimiofossiles or biomarkers. Among animals, arthropods were considered the first land colonizers on the basis of fossil evidence [5-7]. However, it is possible that other wildlife lands may colonize even earlier. Among them, nematodes, Tardigrade and Anneliden are likely to be among the candidates, given their current exploitation of terrestrial environments, but these groups have relatively poor fossil records. The same comparisons between organisms can be made with DNA-coded proteins. For example, each living cell uses a protein called cytochrome c in its energy metabolism. The proteins of cytochrome C in humans and chimpanzees are identical. But there is only an 86% overlap in molecules between humans and ringer snakes, and only 58% overlap between us and the brewing years. This is due to the evolutionary thesis that we recently shared a common ancestor with chimpanzees, while the common ancestor we shared with ringer snakes is much older. Even further in the past, we and Yeast shared a common ancestor – and the molecular data reflect this pattern. Kingdom Fungi, one of the oldest and largest groups of living organisms, is a monophylete group, which means that all modern fungi can be attributed to a single gene organism.
About 800 million to 900 million years ago, this gene organism departed from a common ancestor with animals. Today, many organisms, especially under phycomycetes and mucous membranes, are no longer considered real fungi, although mycologists could study them. This is the case with water forms (for example. B the agent phytophthora, cause of potato water), all of which have been reclassified into the kingdom of Chromista (phylum oomycota). Similarly, amoebidales, parasites or commensales on living arthropods and formerly considered fungi, are considered protozoan animals. None of the mucous forms are placed in the kingdom of fungi and their relationship with other organisms, especially animals, remains uncertain. We used the divergence of centipedes (chilopoda) and centipedes (Diplopoda) as the minimum (more recent) time of arthropod terterdation and the divergence of myriapods with their closest relatives (in this case chelicerate) as the maximum time (the earliest) for myrariapod cephaloization.