Until recently, zoologists believed that all species of phocids (true seals), a pinniped family, use a

different maternal strategy than do otariids (fur seals and sea lions), another pinniped family. Mother otariids use a foraging strategy. They acquire moderate energy stores in the form of

blubber before arriving at breeding sites and then fast for 5 to 11 days after birth. Throughout the rest of the lactation (milk production) period, which lasts from 4 months to 3 years

depending on the species, mother otariids alternately forage at sea, where they replenish their

fat stores, and nurse their young at breeding sites. Zoologists had assumed that females of all phocid species, by contrast, use a fasting strategy in which mother phocids, having accumulated

large energy stores before they arrive at breeding sites, fast throughout the entire lactation period, which lasts from 4 to 50 days depending on the species. However, recent studies on

harbor seals, a phocid species, found that lactating females commenced foraging approximately 6 days after giving birth and on average made 7 foraging trips during the remainder of their 24-day

lactation period.

The maternal strategy evolved by harbor seals may have to do with their small size and the large proportion of their fat stores depleted in lactation. Harbor seals are small compared with other

phocid species such as grey seals, northern elephant seals, and hooded seals, all of which are known to fast for the entire lactation period. Studies show that mother seals of these species use

respectively 84 percent, 58 percent, and 33 percent of their fat stores during lactation. By

comparison, harbor seals use 80 percent of their fat stores in just the first 19 days of lactation, even though they occasionally feed during this period. Since such a large proportion of their fat

stores is exhausted despite feeding, mother harbor seals clearly cannot support all of lactation using only energy stored before giving birth. Though smaller than many other phocids, harbor

seals are similar in size to most otariids. In addition, there is already some evidence suggesting that the ringed seal, a phocid species that is similar in size to the harbor seal, may also use a

maternal foraging strategy.

Noun �(N) Verb�V Adjective�AJ Adverb� AV

Until recently (AV), zoologists (N) believed (V) that all species (N) of phocids (true seals) (N), a

pinniped (AJ) family (N), use (V) a different (AJ) maternal (AJ) strategy (N) than do otariids (N) (fur seals and sea lions), another pinniped (AJ) family (N). Mother Otariids (N) use a foraging (AJ) strategy

(N) . They acquire (V) moderate (AJ) energy (AJ) stores (N) in the form (n) of blubber (N) before arriving (ADJ – present participle) at breeding (AJ) sites (N) and then fast (V) for 5 to 11 days after

birth (N). Throughout the rest (N) of the lactation (AJ) (milk production) period (N), which lasts (V) from 4 months to 3 years depending (Present participle - adjective) on the species (N) , mother

otariids (N) alternately (AV) forage (V) at sea, where they replenish (V) their fat (AJ) stores, and nurse (V) their young (N) at breeding (AJ) sites (N) . Zoologists (N) had assumed (V) that females (N) of all

phocid (AJ) species (N) , by contrast (N), use a fasting (AJ – present participle) strategy (N) in which

mother phocids, having accumulated (Past participle - adjective) large (AJ) energy (AJ) stores (N) before they arrive (V) at breeding (AJ) sites (N), fast (V) throughout the entire lactation (AJ)

period (N), which lasts (V) from 4 to 50 days depending on the species. However, recent (AJ) studies on harbor seals, a phocid species, found (V) that lactating (Present participle - adjective)

females commenced (V) foraging (Gerund - noun) approximately 6 days after giving (Present Participle - Adj) birth and on average made (V) 7 foraging (AJ) trips (N) during (Preposition) the

remainder (N) of their 24-day lactation (AJ) period (N). The maternal (AJ) strategy (N) evolved (past participle - Adj) by harbor seals may (V) have to do (V - infinitive) with their small (AJ) size

(N) and the large (AJ) proportion (N) of their fat (AJ) stores (N) depleted (Past participle - adj) in

lactation (N). Harbor seals are small (AJ) compared (Past participle - adj) with other phocid species such as grey (AJ) seals, northern (AJ) elephant seals, and hooded (AJ) seals, all of which are

known to fast for the entire (AJ) lactation period (N). Studies (N) show (V) that mother seals of these species use respectively 84 percent, 58 percent, and 33 percent of their fat stores during lactation. By

comparison, harbor seals use 80 percent of their fat stores in just the first 19 days of lactation, even though they occasionally (AV) feed (V) during (prep) this period. Since such a large proportion of

their fat stores is exhausted (Passive Verb) despite (preposition) feeding (Gerund - noun), mother harbor seals clearly (AV) cannot support (V) all of lactation using (Adj – Present Participle_

only (ADJ) energy (N) stored (Past participle - adj) before giving (Adj – present participle) birth

(N). Though smaller (AJ) than many other phocids, harbor seals are similar (AJ) in size to most otariids. In addition (prepositional phrase), there is already some (AJ) evidence (N) suggesting

(present participle - adj) that the ringed (AJ) seal, a phocid species that is similar in size to the harbor seal, may also use a maternal (AJ) foraging (Present Participle – Adj) strategy (N).

During the nineteenth century, occupational information about women that was provided by the

United States census—a population count conducted each decade—became more detailed and precise in response to social changes. Through 1840, simple enumeration by household mirrored

a home-based agricultural economy and hierarchical social order: the head of the household (presumed male or absent) was specified by name, whereas other household members were only

indicated by the total number of persons counted in various categories, including occupational

categories. Like farms, most enterprises were family-run, so that the census measured economic activity as an attribute of the entire household, rather than of individuals.

The 1850 census, partly responding to antislavery and women's rights movements, initiated the

collection of specific information about each individual in a household. Not until 1870 was occupational information analyzed by gender: the census superintendent reported 1.8 million

women employed outside the home in "gainful and reputable occupations." In addition, he

arbitrarily attributed to each family one woman "keeping house." Overlap between the two groups was not calculated until 1890, when the rapid entry of women into the paid labor force

and social issues arising from industrialization were causing women's advocates and women statisticians to press for more thorough and accurate accounting of women's occupations and

wages.

Adjective (A), Past Participle (PP), Present Participle (PR-P), Noun (N), Gerund (G),

Verb (V)

During (Prep) the nineteenth (A) century (N), occupational (A) information (N) about women that was provided (Passive Verb) by the United States (A) census (N) —a population (A)

count (N) conducted (PP) each decade—became (V) more detailed (A) and precise (A) in

response to social (A) changes (N). Through 1840, simple (A) enumeration (N) by household (N) mirrored (V) a home-based (A) agricultural (A) economy (N) and hierarchical (A) social

(A) order (N): the head (N) of the household (N) (presumed male or absent) was specified (Passive Verb) by name, whereas other (A) household (A) members (N) were only indicated

(Passive Verb) by the total (A) number (N) of persons (N) counted (PP) in various (A) categories (N), including (PR-P) occupational (A) categories (N). Like farms (N), most

enterprises (N) were family-run (Passive Verb), so that the census (N) measured (V)

economic (A) activity (N) as an attribute (N) of the entire (A) household (N), rather than of individuals (N).

The 1850 (A) census (N), partly responding (PR-P) to antislavery (A) and women's-rights (A)

movements (N), initiated (V) the collection (N) of specific (A) information (N) about each

individual (N) in a household (N). Not until 1870 was occupational (A) information (N) analyzed (Passive Verb) by gender (N): the census (A) superintendent (N) reported (V) 1.8

million women (N) employed (PP) outside the home (N) in "gainful (A) and reputable (A) occupations (N)." In addition, he arbitrarily attributed (V) to each family one woman "keeping

(PR-P) house (N)." Overlap (N) between the two groups (N) was not calculated (Passive Verb) until 1890, when the rapid (A) entry (N) of women (N) into the paid (PP) labor (A) force

(N) and social (A) issues (N) arising (PR-P) from industrialization (N) were causing (V)

women's (A) advocates (N) and women (A) statisticians (N) to press (Verb – infinitive) for more thorough (A) and accurate (A) accounting (G) of women's (A) occupations (N) and wages

(N).

The general density dependence model can be applied to explain the founding of specialist firms

(those attempting to serve a narrow target market). According to this model, specialist foundings hinge on the interplay between legitimation and competitive forces, both of which are

functions of the density (total number) of firms in a particular specialist population. Legitimation occurs as a new type of firm moves from being viewed as unfamiliar to being viewed as a natural

way to organize. At low density levels, each founding increases legitimation, reducing barriers to

entry and easing subsequent foundings. Competition occurs because the resources that firms seek—customers, suppliers, and employees—are limited, but as long as density is low relative to

plentiful resources, the addition of another firm has a negligible impact on the intensity of competition. At high density levels, however, competitive effects outweigh legitimation effects,

discouraging foundings.

The general (A) density-dependence (A) model (N) can be applied (V) to explain (V-infinitive)

the founding of (G) specialist (A) firms N) (those attempting (PR-P) to serve (V-infinitive) a narrow (A) target (A) market (N)). According to this model (N), specialist (A) foundings (N)

hinge (V) on the interplay (N) between legitimation (N) and competitive (A) forces (N), both of which are functions (N) of the density (N) (total (A) number (N)) of firms (N) in a particular

(A) specialist (A) population (N). Legitimation (N) occurs (V) as a new (A) type (N) of firm

(N) moves (V) from being viewed (passive verb) as unfamiliar (A) to being viewed (passive verb) as a natural (A) way (N) to organize (V-infinitive). At low (A) density (A) levels (N),

each founding (N) increases (V) legitimation (N), reducing (Adverbial Modifier) barriers (N) to entry (N) and easing (Adverbial Modifier) subsequent (A) foundings (N). Competition (N)

occurs (V) because the resources (N) that firms seek (V) —customers (N), suppliers (N), and employees (N)—are (V) limited (A), but as long as density (N) is low (A) relative to plentiful

(A) resources (N), the addition (N) of another firm (N) has a negligible (A) impact (N) on the

intensity (N) of competition (N). At high density (A) levels (N), however, competitive (A) effects (N) outweigh (V) legitimation (A) effects (N), discouraging (Adverbial modifier)

foundings (N).