...and over. 65+ years: now 12%; in...
...expectancy: Women 81 years and men 76...
...and men 76 years. Geriatrics: physiological aspects...
...living for 75-84 years: 6% of men...
...in Canada 40 years after age 18...
...retirement at 65 years. Individual justice: support...
...earlier than 65 years. Recently, women are...
...to live 18 years. 9 years disability-free...
...18 years. 9 years disability-free 3 years...
...years disability-free 3 years of slight, 3...
...of slight, 3 years of moderate, and...
...moderate, and 3 years of serious disability...
...than one-fifth of years lost before 65...

...over millions of years. Some fossilized organisms...
...four to six years in temperate forests,...
...to a few years. The difference is...
...can take 50 years or longer. Algae...
...bedrock. During most years, the forest actually...
...herbicides for three years to prevent regrowth...
...Over the three years, water runoff from...
...absent. The 45 years of data from...
...monitored over two years before using a...
...the past 40 years. In the United...
...the environment for years or even decades....
...period. After ten years, trees in the...
...half a million years old. Prehistoric temperatures...
...the past 100,000 years. The ecosystems where...
...increased in recent years. The hole sometimes...
...the past 20 years. As a result...
...at least 50 years. Destruction of Earth’s...

...Half a Billion Years of Backbones In...
...period, 540 million years ago, slender 3-cm-long...
...nearly 200 million years, vertebrates were restricted...
...about 360 million years ago, the evolution...
...explosion 530 million years ago. The most...
...in streams for years before migrating to...
...the past 170 years, where it has...
...than 300 million years. Vertebrates with additional...
...about 470 million years ago, and steadily...
...period, 360 million years ago. Sharks and...
...than 300 million years. Now chondrichthyans are...
...75% in 15 years. The clade Osteichthyes...
...of thousands of years. Recently, industrial-scale fishing...
...extinct 75 million years ago, has been...
...place 360 million years ago, when the...
...from 365 million years ago had bony...
...the past 25 years, zoologists have been...
...about 370 million years ago. No fossils...
...some 320 million years ago. Reptiles have...
...arose 310 million years ago. The oldest...
...about 310 million years ago. The first...
...out 200 million years ago, at the...
...period, 65 million years ago, pterosaurs had...
...least 220 million years ago, when they...
...New Zealand 750 years ago, the rats...
...are 220 million years old, with fully...
...about 150 million years ago, during the...
...boundary, 65.5 million years ago. Most birds...
...Triassic, 200 million years ago. These animals...
...about 12 million years ago and then...
...about 3 million years ago when the...
...to 100 million years ago by molecular...
...and 60 million years ago by morphological...
...about 45 million years ago, support the...
...about 20–25 million years ago and are...
...than 3.5 billion years, humans and apes...
...past few million years. Our own species,...
...is about 200,000 years old. Human evolution...
...lived 6–7 million years ago. Sahelanthropus and...
...lived 4.5–4 million years ago, show that...
...and 2 million years ago. The various...
...and 2.4 million years ago. From skeletons,...
...least 1 million years. A. afarensis had...
...of 30–35 million years ago were tree-dwellers....
...tree-dwellers. Ten million years ago, the forests...
...About 1.9 million years ago, hominins living...
...to 1.5 million years old. This species...
...from 1.9–1.6 million years ago are recognized...
...back 1.8 million years, were discovered in...
...sometime after 200,000 years ago. In Europe,...
...Africa about 600,000 years ago and spread...
...throughout Europe 200,000–30,000 years ago. Neanderthals lived...
...East by 200,000 years ago but never...
...extinct about 28,000 years ago. Preliminary results...
...back about 115,000 years, from the Middle...
...date at 15,000 years ago. In 2004,...
...from just 18,000 years ago and representing...
...them. By 36,000 years ago, humans were...
...the past 200,000 years. The evolutionary change...

...arose 570 million years ago. The basic...
...(about 575 million years ago). Most major...
...more than 40 years. Most monogeneans are...
...than 35 million years. Bdelloid rotifers raise...
...lived 400 million years ago. The phylum...
...of millions of years until their disappearance...
...from 450 million years ago. Arthropods have...
...about 416 million years ago. When insect...
...about 90 million years ago. Although insect...
...past 65 million years. Flight is one...
...from 500 million years ago could pass...
...half a billion years. Lecture Outline for...

...half a billion years. The animal kingdom...
...the last billion years. Some estimates based...
...about a billion years ago. Similar studies...
...to 875 million years ago. A combination...
...(1 billion–542 million years ago) Despite molecular...
...to 550 million years old. These fossils...
...Era (542–251 million years ago) Animals underwent...
...and 525 million years ago, during the...
...By 460 million years ago, arthropods began...
...least 302 million years ago, suggesting that...
...about 360 million years ago and diversified...
...Era (251–65.5 million years ago) No fundamentally...
...Era (65.5 million years ago to the...
...than 500 million years. This early evolutionary...
...least 535 million years. Animal body plans...

...about 360 million years ago. A seed...
...angiosperms), began 13,000 years ago. Humans began...
...first 100 million years of life on...
...for days or years. Under favorable conditions,...
...about 360 million years ago. Angiosperms arose...
...than 200 million years later. The earliest...
...about 305 million years old. These early...
...Permian, 251 million years ago, geologists use...
...more than 4,600 years old and may...
...takes nearly three years for male and...
...about 140 million years old. During the...
...period, 100 million years ago, angiosperms began...
...about 305 million years ago. This does...
...originated 305 million years ago, but it...
...of plants 13,000 years ago. In maize,...
...forests within 100–150 years. The most common...
...the next 100–200 years, 50% or more...

...first 3 billion years of Earth’s history,...
...about 1.2 billion years ago. About 500...
...About 500 million years ago, plants, fungi,...
...about 370 million years ago, taller plants...
...from 420 million years ago show that...
...first 100 million years that terrestrial communities...
...about 420 million years. Unlike bryophytes, these...
...roots 400 million years ago, when the...
...record 410 million years ago; megaphylls do...
...about 370 million years ago. According to...
...over millions of years, heat and pressure...

...Five hundred million years ago, Antarctica was...
...about 4.6 billion years ago, condensing from...
...few hundred million years after Earth’s formation....
...about 3.9 billion years ago. Abiotic synthesis...
...the number of years it takes for...
...half-life of 5,730 years. Uranium-238 decays slowly,...
...of 4.5 billion years. Fossils contain isotopes...
...to about 75,000 years old. Fossils older...
...of 1.3 billion years old. If the...
...and 535 million years old, the fossils...
...about 530 million years ago. The magnetism...
...approximately 4 billion years. These two eons...
...last half billion years and encompasses much...
...existed 3.5 billion years ago, it seems...
...perhaps 3.9 billion years ago, when Earth...
...to 2.0 billion years ago. The evolution...
...About 2.7 billion years ago, oxygen began...
...and 2.2 billion years ago, it shot...
...lived 1.5 billion years ago. The oldest...
...lived 1.2 billion years ago. Large and...
...record 600 million years ago. The Ediacaran...
...to 545 million years ago. Why were...
...to 580 million years ago. At times...
...about 575 million years ago. Many phyla...
...Within 10 million years, predators longer than...
...and 700 million years ago. Recent fossil...
...from 570 million years ago, including beautifully...
...about 500 million years ago. The colonization...
...than a billion years ago. However, macroscopic...
...about 500 million years ago, during the...
...About 420 million years ago, small plants...
...leaves. Fifty million years later, plants had...
...about 365 million years ago and appear...
...to 7 million years ago. Our species...
...originated about 160,000 years ago. Concept 25.4...
...eukaryotes 1.5 billion years ago, there have...
...and 250 million years ago) in which...
...roughly 250 million years from now. Earth’s...
...About 250 million years ago, all the...
...past 15 million years. Continental drift promotes...
...last 500 million years. In each mass...
...than 5 million years. Terrestrial life was...
...of 65 million years marks the boundary...
...the last 400 years. This rate is...
...to 10 million years for diversity of...
...took 100 million years for the number...
...dinosaurs 65 million years ago. Although mammals...
...originated 180 million years ago, they remained...
...least 35 million years before the Cambrian...

...seasons, or different years cannot mix gametes....
...than 2 million years ago, small populations...
...began 88 million years ago, when the...
...trees. About 200 years ago, some populations...
...the last 100,000 years from a small...
...more than 20 years of studying the...
...for 5 million years, but most of...
...the first 50,000 years of its existence—just...
...short as 50,000 years (in geologic terms)...
...of thousands of years, this period of...
...over millions of years. A growing number...
...ranged from 4,000 years (Ugandan cichlids) to...
...to 40 million years (some beetles). Overall,...
...averaged 6.5 million years and rarely took...
...less than 500,000 years. These data suggest...