Leigh M. Van Valen (August 12, 1935 - October 16, 2010) was an American evolutionary biologist known for his contributions to taxonomy and evolutionary theory. He proposed the Red Queen hypothesis in 1973, complementing his law of extinction, which concerned the constant probability of extinction among closely related families of organisms. He defined the Ecological Species Concept in 1976 and suggested in 1991 that HeLa cells be defined as a new species called Helacyton gartleri. Van Valen was a professor at the University of Chicago's Department of Ecology and Evolution.
Zodiac Sign (Western)
Sunsign, Tropical Zodiac
Zodiac Sign (Vedic)
Moonsign, Sidereal Zodiac
Age (Today)
Your next birthday is 295 days away.
Death Anniversary
Next death anniversary is 4 days away.
Death Date
Place of Birth
Time Zone - America/New_York (4:0 W)
Chinese Zodiac Sign
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Name Number (Chaldean)
Name Number (Pythagorean)
Meaning of the name - Leigh
meadow, clearing in a forest
Read Full Leigh Name AnalysisAugust 12, 1935 Facts
Generation Group
Leigh Van Valen belongs to the Silent Generation group.
Place of Birth: Albany
Place of Death: Chicago
Cause of Death: leukemia
Occupation: biologist
Employers: University of Chicago
Astrology Analysis
Note: This birth chart is calculated using the date and place of birth, with the time set to noon (12:00 PM) local time. While this provides accurate planetary positions for most celestial bodies, the Ascendant (Rising Sign) and house cusps are not calculated since they require precise birth time. For a complete astrological analysis including houses and rising sign, please provide the exact birth time.
Ephemeris for August 12, 1935
Note: Moon position is location and time sensitive.| Planet | Position (Tropical, Western) | Transits on August 12, 2025 | Secondary Progressions for August 12, 2025 |
|---|---|---|---|
| Sun | 19 Leo 0 | 20 Leo 12 | 17 Scorpio 19 |
| Moon | 23 Capricorn 3 | 3 Aries 7 | 18 Taurus 3 |
| Mercury | 21 Leo 48 | 4 Leo 21 | 0 Scorpio 53 |
| Venus | 22 Virgo 13 | 14 Cancer 35 | 0 Libra 54 |
| Mars | 7 Scorpio 52 | 3 Libra 34 | 9 Capricorn 39 |
| Jupiter | 14 Scorpio 41 | 14 Cancer 10 | 0 Sagittarius 9 |
| Saturn | 8 Pisces 20 | 1 Aries 3 | 3 Pisces 39 |
| Uranus | 5 Taurus 31 | 1 Gemini 14 | 2 Taurus 57 |
| Neptune | 13 Virgo 22 | 1 Aries 46 | 16 Virgo 20 |
| Pluto | 26 Cancer 16 | 2 Aquarius 9 | 27 Cancer 22 |
| Rahu | 20 Capricorn 24 | 19 Pisces 39 | 15 Capricorn 38 |
| Ketu | 20 Cancer 24 | 19 Virgo 39 | 15 Cancer 38 |
Chandra Kundali (Equal House, North Indian Diamond Chart)
