Extinct species

Amber deriving from the extinct species Pinus succinifera is known as Baltic amber or succinite and consists of dimers of abietic acids and copolymers of communol and communic acid. Amber is less soluble than the other resins, but partially soluble in hot oil, so it has been used as an ingredient in varnish. 

In the present-day ocean, about half of the PIC exported to oceanic sediments consists of the remains of foraminiferans. These microorganisms are protozoans. They are widespread in the marine environment with some species having a pelagic lifestyle and others benthic. As shown in Figure 15.1a, their calcareous structures have the appearance of a chambered snail shell and are composed of the mineral calcite. Since this hard part is covered by tissue, it is technically a type of skeleton. These detrital remains are referred to as tests or forams. Among the present-day and extinct species of foraminiferans, considerable variation exists in the size, shape, and density of their tests. 

Polymerase chain reaction has also proven to be useful in the fields of archaeology and evolution. Ancient biological samples recovered from digs and expeditions can be subjected to PCR to gain insight into the genetic composition of extinct species, including some of our earliest ancestors. The information obtained from these... 

Keller G. R., Barrera E., Schmitz B., and Mattson E. (1993) Gradual mass extinction, species survivorship, and longterm environmental changes across the Cretaceous-Tertiary boundary in high latitudes. Geol. Soc. Am. Bull. 105,... 

Amber is the generic name for all fossil resins secreted in prehistoric times by certain types of evergreens, now extinct. This resin was produced in the Oligocene age by exudation from a now extinct species of pine. 

The chemical nature of amber is complex. Amber consists of complex mixtures of sesquiterpenoids, diterpenoids, and triterpenoids that have undergone polymerization and molecular reorganization during fossilization. Phenolic units may also be present. Baltic coast deposits, which contain about 8% succinic acid, are often called succinite. Amber is amorphous, and its infrared spectrum closely resembles those of nonvolatile resins from extinct pine trees. It is believed not to be a high polymer, the resinous state being accounted for by the complexity of materials present. Amber also serves as a repository for a variety of extinct species of insects. 

Ted Turner owns more land in America than any other single individual—about 2 million acres, most of it made up of fifteen immense ranches sprawled across six states, primarily in the West. When the federal government needs help reintroducing nearly extinct species to their old ranges—wolves, ferrets, bears, trout, woodpeckers—it turns to Turner. His mission is as simple as it is unprecedented As much as practically possible, he is attempting to return his lands to the natural state in which they once existed, before man came along. 

Some of the more spectacular uses of PCR include cloning of ancient DNA from extinct species such as the woolly mammoth ruling out suspects in criminal cases by forensic science, and providing genomic markers (STSs) in chromosome-mapping studies used in the Human Genome Project (see Chapter 21). 

Museum and archive specimens demand and warrant a level of protection from pests (primarily Insects, occasionally fungi) that approaches absolute. Historical artifacts and preserved members of extinct species are not, unlike commercial products, renewable commodities. Consequently, a damage threshold or allowable loss level Is not possible If valuable collections are to be maintained. Most collections are, however, dynamic, with the addition of new Itons, and the removal of others for loan or study, constantly taking place. Both the storage and the flux of a viable collection have the potential for Infestation and Irreparable damage. Therefore, pest protection Is an Important and constant responsibility of a museum s staff. 

If not already now, then at least very soon, experts in the old survey skills will be an extinct species or too old to be sent into the hazardous conditions abroad. The young and entrepreneurial survey executives of today want MegaBytes and MegaHz at their fingertip abroad as weU as at home. They are eager to proliferate their know- how with the same ardent missionary drive their ancestors in more transcendental affairs were willing to die for 200 years ago. 

PCR is being used in phylogenetic and evolutionary studies. PCR amplification and screening of ribosomal RNA (rRNA) genes and mitochondrial DNA have been used to estimate relationships between species and subspecies. Besides studies on the relationships of contemporary species, PCR allows studies on extinct species because it can be performed on material in museum collections. Amplification and sequencing of mitochondrial DNA are also used in evolutionary studies. 

Fossil resin n. A natural resin obtained from fossilized remnants of plant or animal hfe. An example is amber, a fossilized resin derived from an extinct species of pine. 

DNA sequencing is not limited to modern samples. Scientists have amplified DNA from ancient human remains and extinct species, including DNA that was more than 64,800 years old. 

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