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worm becomes a fly with wings), there must be matching mutations, which, after all, origi­

nate from the preform. This leads to the fact that in developmental biology, the earlier

stages of evolution are often caught up (Häckel’s law: every ontogeny, i.e. every individual

development, recapitulates phylogenesis, i.e. the phylogeny). Genetics, for example with

the help of the OMIM database, also helps to uncover gene relationships and mutation

possibilities. More recently, better and better computer simulations have also become pos­

sible and allow insights (e.g. with regard to transposons) into a genome or, as an example

from our own work, with regard to phage infection and cell wall metabolism (Winstel

et al. 2013). Indeed, such processes accelerate evolution in the affected organisms (trans­

posons jump and disrupt or modify genes) or slow it down (in our example, modified cell

wall synthesis prevented infection with certain bacteriophages, which allowed the bacteria

to evolve more separately from other staphylococci). In this way, both through phyloge­

netic trees and sophisticated new computational models, bioinformatics allows a new,

detailed and more accurate analysis of evolution and its mechanisms (Connallon and Hall

2016). This also underpinned fascinating new insights into the evolution of life such as the

endosymbiont hypothesis (e.g. bioinformatics analysis of organelle gene sequences trans­

ferred to the nucleus) and the RNA world (e.g. computational elucidation of ribosome

structure, which revealed that peptide binding in the ribosome occurs through catalytic

ribosomal RNA).

Since the advent of next generation sequencing, a very fast sequencing method, it has

been possible to sequence environmental samples and characterise the mixture of organ­

isms present in the sample without having to cultivate the organisms. The individual

sequence fragments must be assigned to the individual genomes (metagenomics). The sum

of the DNA in such an environmental sample is called a metagenome. With the usual cul­

ture methods, cultivation is only successful for 1–2% of organisms. Metagenomics thus

significantly expands our knowledge of biological diversity. A synopsis of the new micro­

bial diversity including detailed evolutionary analyses and new phylogenetic trees is given

by Castelle and Banfield (2018). Five times more bacterial phyla (“strains”, comparable to

all vertebrates or all arthropods) are revealed than were recognized before these new meth­

ods. One can also prove very clearly with it that the higher cells (cells with real cell

nucleus) represent indeed clearly a side branch of the Euryarchaeota, thus go back to the

Archaebacteria and then have taken up additionally as energy factories with the mitochon­

dria gamma-Proteobacteria or with the chloroplasts former blue-green algae, which drive

then photosynthesis in the plants. With the higher cells (with cell nucleus, the eukaryotes),

there are besides the animals and plants (“kingdoms”) on the same level also the fungi. But

this is only a small side branch of the archaebacteria in the phylogenetic tree. All bacteria

(prokaryotes) make up the mass of the diversity of life, the archaebacteria seem only

slightly less diverse than the eubacteria (the typical bacteria like gram-negative coliform,

gram-positive like staphylococci and Bacillus subtilis, and completely new groups). All

other life (animals, plants, fungi, higher protozoa) is just a small side branch. And to make

matters worse, the impressive bacterial diversity is five times greater than was even thought

possible just a few years ago.

10.1  A Brief Overview of Evolution from the Origin of Life to the Present Day