Diversity Of Life On Earth Essay

Introduction

Fossil records indicate life has existed on this planet for at least 3.8 billion years. Most species that have ever existed are now extinct, yet the diversity of life on Earth is still so tremendous and complex scientists estimate there are 10-100 million species yet to be documented. Those that have been documented, have been categorized it into three domains, six kingdoms, twenty-nine phyla, and countless more subdivisions. Seemingly in spite of this diversity, a common ancestry unites all life on Earth. From mosses on trees to bonobos in Zaire, all life shares special characteristics that bind us together. The most substantial evidence of this relatedness has come from careful examination of specimens from the fossil record, as well as the sequencing of genomes from many organisms.

Humans are heavily reliant on the diversity of life that occurs on Earth; from the microbes in soil, to oxygen producing plants and pollinating insects, to the animals we eat and wear and to the trees we cut down, reorganize and live in, human existence – as we know it – is completely dependent upon a tremendous diversity of life on this planet. We are going to explore the domains and kingdoms into which life is categorized in hopes of better understanding the unity and diversity of life on Earth.

Domains: Archea and Bacteria

Characteristics of these domains

Perhaps the most readily noticeable characteristic of archaea and bacteria is their size. These domains are comprised of the smallest, self-sustaining forms of life on the planet. Bacteria and archaea are prokaryotic, thus lack a nuclear envelope and membrane-bound organelles. They also present with circular chromosomes, sometimes referred to as “ring-DNA”. Many archaea are known a...

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...ironment affects the organism. When organisms disappear from environments and ecosystems, other species that have come to rely on them through millions of years of coevolution are almost invariably impacted for the worse.

Our actions as humans have setoff what scientists recognize as the sixth mass extinction event. At a time when the global, human population is as high it has ever been, and is still growing rapidly, more and more pressure is being applied to ecosystems and habitats of all types, all over the globe. Though this planet is finite, and thus cannot be “saved”, it is largely in human hands how long we and the remaining species of life exist. Perhaps we, as a species, will awaken to plight with which we are burdening our progeny and correct our course. Alternatively, we may continue on, helping nature select against beings of “higher” intelligence.